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Monday, June 30, 2008

Art societies and art galleries - data protection, privacy and you

Four questions for you - and your art society and/or art gallery:
  1. Does your art society and/or art gallery understand that it has to protect personal data relating to individuals?
  2. Are the administrators 'data protection aware'?
  3. Do they process personal information about individuals in a secure way?
  4. Are the officers of your art society / managers of your art gallery aware of their legal responsibilities under data protection legislation?
RHS Tulip #1
8"x8"coloured pencils on Arches HP
copyright Katherine Tyrrell

We all hear from time to time about the activities of fraudsters - but do we ever stop to think about how they get hold of identity information and how they might get hold of yours?

You might be taking appropriate action to safeguard your identity online and at home. But are you sure that the organisations which you give your personal data are equally careful?

Mailing lists - whether actual addresses or e-mail addresses - are bread and butter fodder for fraudsters. Organisations which engage in fraud buy and sell mailing lists all the time - and they're always on the look out for weaknesses in data protection.

In Europe, unlike the USA, there is a strict legal regime about data protection. Broadly speaking, if an individual can be identified from the data then it's personal data and is protected.

This regime is about to get a lot more strict in the UK with the introduction of the new Criminal Justice Act - this introduces new civil penalties for serious beaches of data protection principles. The new legislation gives the Office of the Information Commissioner the power to impose substantial fines on any organisations that deliberately or recklessly commit serious breaches of the Data Protection Act.

Data protection is an area where art societies and art galleries have no option but to behave in a strictly professional and business-like way. But the sad fact is that at present rather too many don't.

It's clear to me that more than a few art societies, art galleries and other art-related organisations covered by the legislation are completely unaware of their legal obligations concerning the protection of the personal data of their members. If they're unaware, then it's very unlikely that their administrative process also comply with European data protection legislation.

Art organisations and problems with data protection

The reason I'm raising this issue today is because at the weekend I became aware of yet another art organisation which has failed to protect personal data.

Here are some examples of the sorts of failures to protect personal data which I've come across in recent times. I'm not naming the individual art societies or galleries because frankly lax practice seems to be pretty widespread and it seems invidious to name one and not others.
  • An email sent to me about an event by an organisation acting on behalf of an art society disclosed its complete mailing list and all the e-mail addresses on it to everybody on that mailing list.
  • Another art society recently sent me its handbook. It contained every member's name, address, telephone number and e-mail address. Apart from the fact that I don't need all of this information, it represents a fraudster's dream come true.
  • An art society had a laptop stolen recently. It contained all the personal contact details of all its members. The data was not encrypted.
  • A fourth (and fifth and sixth and seventh....) art society lists the home addresses and telephone numbers of all its members in the brochure for its annual exhibition.
The conclusion I've come to is that a number of organisations are being run by people who have no contact with the wider business world and/or awareness of data protection obligations. They simply do not know what's required or about any changes in data protection legislation.

However, I'm afraid that rationales such as "we've always done it like this and it's always been OK before" and "we're just amateurs, we don't know about these things" are no legal defence and simply do not excuse what is happening.

Ultimately, what we're talking about here is data protection and privacy - and these are matters which will be coming within the jurisdiction of criminal law in the UK in the very near future.

This blog post aims to raise awareness of this issue. If all those reading it asked their own art societies and art galleries (and themselves) the questions I am posing then maybe we might see the basics being addressed rather better than they are at present.

Data protection - what are the basics?

Unlike the USA, the right to privacy is a highly developed area of law in Europe and data protection legislation has been around for a very long time.

10 years ago an effort was made to harmonize it so that the same principles applied across all member states of the European Union (see links below for more details). The European Directive on the protection of personal data provided the basis for all national legislation.

In the UK, the Data Protection Act 1998 required all organisations which handle personal information to comply with a number of important principles regarding privacy and disclosure of information which can be used to identify an individual person.

Two sites provide accessible information about the Data Protection Act covers and what it means.
The Act states that anyone who processes personal information must comply with eight principles.........All organisations must make sure that they comply with the Data Protection Act.

But what are the eight principles for processing personal information?
Anyone who processes personal information must comply with eight principles, which make sure that personal information is:
  • Fairly and lawfully processed
  • Processed for limited purposes
  • Adequate, relevant and not excessive
  • Accurate and up to date
  • Not kept for longer than is necessary
  • Processed in line with your rights
  • Secure
  • Not transferred to other countries without adequate protection
Information Commissioner's Office: Personal Data - the basics
More detail about Data protection

This is the Data protection Guide and Guidance. This is the place to start if you or your organisation need to review what's required and then set about implementing their requirements/recommendations if you've not done so already.

The overall priority is that personal data should not be accessible to people who don't need to know it and that personal data should not be published.

These are some particularly relevant sections
Some practical suggestions - do's and don'ts

Any Art Society or organisation dealing with personal data can usefully start by considering the following when devising a potential policy and practical rules for handling personal data:

Personal data includes anything which is linked to an individual eg home address, telephone number, email address etc.

DO
  • Do collect only what is needed. Personal data capable of identifying individuals should only ever collected if it is needed and should only ever be used for the purpose for which it is collected.
  • Do explain why you are collecting personal data and the safeguards. Make sure you identify to the individual the reasons why you need to collect data, what it may be used for, who needs access to it and how you safeguard personal data. Identify how you are going to publicise the existence of a data protection/privacy policy. It's a good idea to link to a formal statement of the data protection / privacy policy on the organisation's website.
  • You MUST get written consent of an individual BEFORE you publish their personal data or or pass it on to anybody else. You cannot assume this and it's not good practice to make it difficult for people to tell you. Best practice is to assume a default that it cannot be published and cannot be passed on.
  • Do keep personal data only for so long as it is needed. Data protection policies need to address what records must be archived, what should be destroyed and how often.
  • Do keep all personal data secure - paper files as well as digital ones.
  • Do make sure that personal data is only ever accessible to those with a 'need to know'.
  • Do train people. Make sure all people handling personal data know and understand basic practices for protecting data.
DO NOT
  • Do not publish personal data without consent in a brochure, leaflet, catalogue, mailing list, email distribution lists etc. without the consent of the person concerned. Do look at what practices you now need to change as a result.
  • Do not assume consent. You cannot assume consent - and your data practices need to assume consent will be withheld by some people - like me! (I have a simple principle which is that I don't assume other people know how to look after my personal data so I always provide the absolute minimum and always refuse permission for it to be shared with any third parties).
  • Do not send out an e-mail to a mailing list without first checking that each recipient ONLY sees their own e-mail address.
  • Do not record financial details - if you can avoid it. These need extra security and you need to find out first how to encrypt them.
  • Do not record personal data on a laptop. If you do then additional security provisions are required (eg encryption and/or use of a password to access data)
  • Do not give personal data away. It's not yours to give - even if it's another art society member who is asking.You need a system which safeguards the personal data of all those people who do not want it to be shared. Default should always be 'do not share'. You can act as a postbox for anybody wanting to contact a third party.
  • Do not sell personal data - it's not yours to sell.
  • Do not exchange personal data for some benefit - it's not yours to give away. - even to a sponsor.
  • Do not leave responsibility for dta protection vague. Identify who is responsible for leading on data protection - policy development and implementation. Identify the minimum to expect people to know and understand.
Q: What security measures should I have in place to protect personal information on laptops?
Where the information held on a laptop or other portable device could be used to cause an individual damage or distress, in particular where it contains financial or medical information, they should be encrypted. The level of protection provided by the encryption should be reviewed and updated periodically to ensure that it is sufficient if the device was lost or stolen, you may need to seek specialist technical advice. In addition to technical security, organisations must have policies on the appropriate use and security of portable devices and ensure their staff are properly trained in these. If it is brought to the Commissioner's attention that laptops that have been lost or stolen have not been protected with suitable encryption he will consider using his enforcement powers.
A data protection checklist - questions to ask your art society, your art gallery and yourself
  1. Are you aware that you have a legal responsibility to protect all personal data which can identify an individual?
  2. Do you know and understand the eight principles of data protection?
  3. Have you implemented the eight principles in the way you process and store the personal data of members or people on your mailing list?
  4. Have the people handling personal data been trained in data protection?
  5. Have you ever sold the mailing list to a third party?
  6. Where can I find a copy of your data protection/ privacy policy?
If you live in the USA this doesn't apply to you. You have to be your own data protection unit! Nevertheless the general principles are sound and it's reasonable to expect that organisations will follow them - so why don't you ask the questions anyway?

Links
on 8 comments:

Sunday, June 29, 2008

29th June 2008 - Who's made a mark this week

Out to Pasture
People write to me from time to time and tell me about what they think about my blog, about their own art and what they are doing. If their blog looks interesting I tend to add it to the list of those that I keep an eye on in Bloglines. Then if they blog consistently and well then I start mentioning them in one of my weekly "Who's made a mark this week?" posts on a Sunday.

Now and again, I see a blog and artwork - and the artist leaps ahead of the queue and gets a feature mention.

Elizabeth St. Hilaire Nelson is a collage artist using paper. She creates "Paper Paintings" from torn bits of hand-made, hand-painted and found papers. Naturally enough, her blog is called Paper Paintings. It's brand new - so I guess many of you won't have found it yet. However she is not brand new as an artist!
What I like about Elizabeth's work is that it is unshamedly collage rather than an artist using a medium and trying to make their work look like something it is not. These are emphatically paintings in my eyes depsite the fact that the only brush involved will have been one with paste on! I also noted that much of work is also well designed. Her use of colour demonstrates to me a very strong and good appreciation of values which makes a lot of her work very eye catching.

Deja Brew
a paper painting by Elizabeth St. Hilaire Nelson

Extracting a post title with URL is becoming DIFFICULT!

Before I start with the body of this post I'd just like to highlight a difficulty I'm having. Copying a post title with an embedded and unique URL has suddenly become well nigh impossible on some blogs. I'm not talking about extracting content here - I'm talking ONLY about being able to copy a blog title with an embedded and unique URL which enables me to send people to visit a precise place in your blog

I like to keep and quote the exact title of a post and copying a title with a unique URL embedded makes life much speedier and more efficient for me. When post titles don't have a unique URL embedded it means that typing out and checking a precise blog title and then copying the URL can take 3 or 4 times longer. Frankly I don't have that sort of time which means that I may well move swiftly on to another blog........

Of late I'm coming across too many blogs which
  • Either - Have NOT yet created settings for post pages so that each post has its own unique URL. (In Blogger you need to go to Archiving/enable post pages and set this to Yes. Post Pages then give each of your posts its own unique web page, in addition to appearing on your blog's front page. It also means that individual posts can appear in browsers as unique pages. All of which generates more traffic and visitors to your blog)
  • OR - are Wordpress blogs which now seem to make it impossible to block and copy the post title to my blog. Any attempt to do so is either impossible or starts to catch other parts of the screen view (eg blogroll)
In this post, there are people whose blogs present me with these sort of difficulties. If I stop linking to you in the future or haven't linked as yet you might like to check out just how easy it is for anybody to reference your blog post on another blog so that they can send you visitors. Why don't you try copying a post title from your own blog - and see what happens......

Meanwhile the solution appears to be to copy the title from Bloglines - which doesn't cause a problem as yet - so long as you are in my Bloglines blogroll..............

Congratulations to.....
  • Richard Childs who has just won the "Wildlife Artist of the Year" award from the David Shepherd Wildlife Foundation at the Mall Galleries. You can see a large image of Richard's work Hope of Sepilok which featured in the last UKCPS annual exhibition on his website. Plus the UKCPS blogpost Some Winners - and a Competition shows a picture of him with David Shephard and Alan Titchmarsh who presented the prizes.
  • Jeanne Grant (Jeanne Grant) in California whose blog is now two years old - Happy Blog Birthday Jeanne. Jeanne was a student in my online Sketching for Real class who's gone from drawing photos at home to being an avid sketcher from life who's also now a member of a plein air art club. You can see a recent example of her work on the right
Art Blogs and Newsletters
Art Practice
Art Book Reviews
  • I've recently taken out membership of Good Reads and now have their widget in my side column. People can list books they own and also do short reviews. I was very much persuaded by the fact that people I like are already members. I luuuuuuurve looking at people's bookcases and this is a way to do so online. The only thing is I now look like a total nerd as I've almost totally given up reading fiction. I have a stack of books about colour next to my bed at the moment!
Art Business and Marketing
With the impact of the credit crunch, here are some alternative perspectives on how to deal with the marketplace Art Materials
Art Exhibitions
Dissatisfaction with modern civilization led Divisionist painters to explore Symbolism. Their aim was to represent political concerns and make their art into an instrument for social change. The movement also sprang from research into optics and the physics of light. Inspired by French developments with pointillism, and fuelled by a desire to increase the luminosity and brilliance of their paintings, artists developed new techniques applying paint in a variety of dots and strokes.
  • On Tuesday, July 1st, J. M. W. Turner - a Special Exhibition opens in The Tisch Galleries at theMetropolitan Museum of Art in New York (July 1, 2008 - –September 21, 2008). This is the first retrospective of the work of J. M. W. Turner (1775–1851) presented in the United States in more than forty years so it rather looks like a MUST SEE for those who can get to New York. It has approximately 140 paintings and watercolors—more than half of them from Tate Britain's Turner Bequest—along with works from other collections in Europe and North America. Turner's range from seascapes and topographical views to historical subjects and scenes from his imagination, is represented. Accompanied by a catalogue.
  • The decision as to what is going on the 4th plinth in Trafalgar Square has been made. It's going to be shared by Antony Gormley and Yinka Shonibare MBE. Antony Gormley proposes that the fourth plinth is occupied 24 hours a day by members of the public who have volunteered to stand on it for an hour at a time. Over a period of 12 months, 8,760 people will take part. You can see the winning designs and the rest of the shortlisted works here plus the Guardian commentary on the choice here Fourth plinth: He wanted to scrap it. Now Boris Johnson could be on it. Plus this is the 4th plinth quiz.
Art Societies
Colour
  • Color Lovers Color and Design Blog has a couple of posts which caught my eye:
  • Plus they also highlighted this fascinating tool Name that Color created by chir.ag - which is when I found out that:
    • a colour I use all the time as a background colour on my website is called "Tusk"!
    • The header for this blog has "Patina" as its central colour and "Laser" in the corners and used as the background colour for all the titles in the right hand column! As a result I tried out the colour names in the Chambers online dictionary and found that the colours are symbolic of this blog being associated with......
Patina: "...any fine finish acquired with age..."
and
Laser: "a device that produces a very powerful narrow beam of coherent light of a single wavelength..."
Chambers Dictionary
Photos of Arcobaleno Pigmenti de Nube Massimo - the pigment shop in Venice
(see Venice - a resource for artists for a map of where it is)
copyright Katherine Tyrrell
Websites and blogging and "being a geek" and finally............

For everybody's new laptop.....

Thanks to Jeanette Jobson (Illustrated Life ) for highlighting the latest in laptop sleeve design. Well naturally, if you live in Canada you take it literally and knit your laptop an arran sleeve. Well - just like you, laptops don't like getting cold!
on 10 comments:

Friday, June 27, 2008

Colour - naming dyes, pigments and paints

While I continue to construct a table of all the different pigment names and colour names (which is turning into a mammoth project - although the end is in sight!) I thought I'd better get on with my planned post about how colours and pigments are named.

My first awareness of colour names came with Michael Wilcox's book analysing watercolour paints The Wilcox Guide to the Finest Watercolours. This was the first time I realised that
  • every pigment has an international classification and standardised name
  • not every colour is what it says it is. In other words the names can continue even if the manufacturers has switched to using different pigments.
  • some of the labelling of watercolour paint has been misleading (an understatement!)
  • some manufacturers refuse to disclose which pigments are in their art media.
Paint labeling is probably the least interesting topic on watercolor paints ... like reading the fire tag on a new mattress. Unfortunately, boredom leads to apathy, and apathy leads to ignorance, and it is this ignorance that paint manufacturers exploit through marketing hype.

Paint labels tell you what your are getting for your money, provided you know the difference between pigments, paints and "colors". If you don't, then marketing gimmicks will take control.
Handprint
First principles for art media communication

I've often heard it said that commercial considerations protect the secrets of how art media is made. I absolutely disagree and suggest this is a fallacy - which is essentially part of marketing hype.

I'd like to highlight a different perspective - one which is very much consumer oriented and very much connected to the whole process of classifying and naming - and selling - pigments, colours and paints.

I believe that
  • artists want to know what they are buying
  • consumers can set the standards for disclosure through the way they buy their art media
  • the following are the principles which a world-class art media manufacturer/distributor SHOULD always observe
I'm passionate about product delivery being consumer oriented and this is my manifesto!
PRINCIPLES FOR WORLD-CLASS DELIVERY OF ART MEDIA TO THE CUSTOMER

All world class manufacturers, distributors and suppliers of art media ("the suppliers") have a duty to support an artist who wants to use good quality materials which are sourced in an ethical way.

World class art media suppliers recognise that supporting an artist is best achieved through the provision of all relevant information in an accessible format.

World class art media suppliers will always disclose:
  • all information relevant to the QUALITY OF THE PRODUCT and
    • lightfastness - the creation of art which will last
    • utility - the behaviour of pigments in a particular art medium
    • toxicity - the safety of an artist
  • all information relevant to an OBJECTIVE ANALYSIS OF QUALITY through
    • standardisation - relevant pigment information as per the international classification for naming pigments and paints
    • clarity - all relevant chemical information
    • toxicity - relevant safety information
    • good communication - the use of labels which conform to international quality standards
  • all information about sourcing which is relevant to ethical considerations
In my view, world class art media suppliers support the notion that colours sold in any art medium should be lightfast, serviceable, not endanger the artist, be described in such a way that the informed artist understands what they are buying and, finally, sourced in ways which are responsible and humane.

Why do I think a consumer-driven approach works?

Well, in my opinion, you only have to look at how the views of society and consumers drive other decisions to change ways in which products are manufactured and distributed - from everything associated with products which have an impact on global warming to the production of battery chickens.

The art world and art materials is essentially no different. Consumers are concerned about quality, safety, reliability and production processes which they think are acceptable.

I very much advocate speaking up and asking for the same information as industry gets (see below).

Standardisation of pigments and paints - international classification

Of course, the reality is that art media form a very small part of the overall market for pigment.

The major industrial uses of pigment and colour - which go way beyond the production of paint - have created the need for standardised quality control. (In other words - the consumers of pigments said they wanted to know what they're buying - see above!).

As a result, there are now international standards and international classification systems and international names for all pigments.

This classification and naming extends to analysis of what a colourant (pigment or dye) is and how it performs - and related to that are a range of other standards about how pigments and dyes should be tested in relation to their constituents and performance.

The International Organization for Standardization (ISO) has developed technical standards for the manufacture of pigments and dyes. ISO standards define various industrial and chemical properties, and how to test for them. The principal ISO standards that relate to all pigments are as follows: ASTM International (ASTM), originally known as the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. It has a Subcommittee on Artists' Paints and Related Materials - ASTM D01.57. It helps artists and consumers recognize product quality and safety when manufacturers' products conform to its Standards.

These are the sort of standards which - if suppliers comply and communicate that compliance - tell consumers an awful lot about whether or not a supplier meets world class standards.
Members of the Subcommittee include artists, educators, conservators, medical doctors, chemists and other materials scientists, and representatives from art materials manufacturers, artists' groups, manufacturers of testing equipment, and regulatory agencies...........ASTM D01.57.has developed and published eleven standards covering such topics as testing of pigments for lightfastness, labeling content, paint performance criteria, and the health hazard labelling of art materials. Three additional standards are currently in development.

ASTM D01.57's mission includes the education of artists through the dissemination of information about the Standards.
ASTM D01.57
So as you can see my "manifesto" is pretty close to what already exists.

From my perspective - the major problem is about gaining manufacturers' compliance with those standards and the communication of information about art media.

For example, one main area of weakness continues to be getting manufacturers to agree and use the same method for classifying lightfastness. One can only speculate as to the reasons why they decline to do so.....

Which is where the artist's voice comes in - it's up to you and me to ask suppliers to comply with recognised standards. It's essentially a question of mutual interest.

What's in a name? The standardisation of pigments and paints names

So - after the need for standards has been recognised and all the testing has been done - FINALLY we get to the standardisation of names.

Many of the names that we use for a lot of colours relate to their historical names. This may now bear absolutely no relation to their actual chemical constituents as substitutions have occurred over the years. Which means that historical pigment and dye names are no longer adequate for providing consumers with adequate information.
The commercial name under which a colorant is marketed does not necessarily give a precise indication of its hue. This is well illustrated by the wide divergence that frequently occurs between the commercial names used by different manufacturers for the same colorant.
color Index International - hue charts
Colour Index International is a reference database of manufactured color products and is used by manufacturers and consumers, such as artists. Colorants (both dyes and pigments) are listed according to Colour Index Generic Names and Colour Index Constitution Numbers.

The Colour Index was first printed in 1925 but is now published exclusively on the web and is jointly maintained by the Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists. It's been adopted by many manufacturers of paints, inks, textiles, plastics, and colors - but NOT all manufacturers of art media

The purpose of the colour index is to have a method for defining colour accurately and objectively. The 4th edition of the Colour Index is now available

In the CII schema, each pigment has a generic index number that identifies it chemically, regardless of proprietary and historic names. The colour index generic name is defined as follows
Color Index Name: A classification name and serial number which when allocated to a commercial product allows the colorant part of that product to be uniquely identified within any Colour Index application class. This enables the particular commercial product to be classified along with other products whose essential colorant is of the same chemical constitution and in which the essential colorant results from a single chemical reaction or series of reactions.
CII - Color Index Name
The CI names for pigments generally start P (for pigment), then have a letter or letters to denote the colour group (eg R = Red) and then a number to indicate the precise chemical composition. This means it becomes a lot easier to tell whether pigment names reflect what the colour is called and whether or not lightfast pigments and dyes are being used.

PW - White pigments PW6 - Titanium white
PY - Yellow pigments PY35 - Cadmium yellow
PO - Orange pigments PO34 - Azo orange
PR - Red pigments PR112 - Naphthol red
PV - Violet pigments PV19 - Quinacridone rose
PB - Blue pigments PB29 - Ultramarine
PG - Green pigments PG7 - Phthalo green
PBr - Brown pigments PBr7 - Natural umber
PBk - Black pigments PBk11 - Oxide black

The CI Constitution number is "an index classification of a colorant or intermediate according to its chemical constitution". Both the name and constitution number represent the chemical composition of the pigments and dyes used in the colouring agent.

The chart at the top is the CII hue chart which is used as part of the color indexing process and is part of the record accessed via the online database. Unfortunately the rest of the database is subscription only - and I understand it's not cheap! I don't quite see how it's ever going to educate the public if it gaurds information in this way. They need to work out a price for a one day access only or view up to x records.

These authors and art suppliers provide listings about pigments and dyes and chemicals and color names
There are others as well - and there are others who provide absolutely no information whatsoever.

In other words it's a complete fallacy that pigment and colour names cannot be supplied. Those suppliers who don't supply them choose not supply artists with relevant information.

I'm thinking about having a post in the future which highlights all those companies which look like they might be seeking to achieve world class status as suppliers of art media - through the provision of excellent information about the quality of their art media!

Tomorrow - what needs to be communicated about pigments and dyes via label, website or brochure.

In the meantime - why don't you check your paints, pencils and pastels - and see if you can tell what pigment or dye has been used and what its chemical composition is................

Links:

The Making A Mark Project on Colour - previous posts
Resources for Artists information sites created by makingamark
on 2 comments:

Thursday, June 26, 2008

Colour - pigments and related colours



From top left clockwise
natural ultramarine; synthetic ultramine; raw sienna, burnt sienna
All Images from Wikimedia

I want a table which tells me all about different colours - and relates pigment to colour names to chemical names and then explains what all that means. But can I find one on the internet? Well I've looked and no I can't! I can find lots of freely available material and some excellent and very informative links - but its all in chunks and I can't find a table which can be looked at offline.

So I'm going to try and produce one. My table will set out the following:
  1. Pigment Groups - natural organic, synthetic organic, and inorganic -
  2. Colour / pigment name (allocated to type of pigment group) - and then for each of these
  3. Chemical Name
  4. Comments abut its use in art
  5. Links to relevant information - which can be opened when viewed online.
It's going to be too big for a blog post to show it properly - mainly because (as I've already discovered!) it needs to be in a landscape format.

So I'm going to produce it as a pdf file and then post it as a FREE Making A Mark Guide in the colour section of my Making A Mark website.

Please feel free to suggest useful websites which can be referenced in the document below!

Check back later today to get a link to it - or, at the very least, an update on how it is progressing! I've got it underway and it's going fine but it's BIG and may take a while............
on 7 comments:

Wednesday, June 25, 2008

Colour - a materials perspective #1 - pigments and dyes

Pigmenti per artisti
- the front window of the pigment shop in Venice
copyright Katherine Tyrrell

This post provides a materials perspective on colour for artists and a basic overview of pigments and dyes. Pigments and dyes are a prime component of the colour used by artists - but
  • Where do they come from?
  • Which are 'old' colours and which are new?
  • What or who creates them?
What materials create colour?

Colour in paint comes from pigments and dyes. All media – oils, watercolours, acrylics, pastels and coloured pencils – are derived from the same pigments and dyes. What actually varies between different media is the vehicle used to bind the pigment together.

Some pigments and dyes have been around for a very long time and some are modern and the result of recent manufacture. Basic colour knowledge relating to materials covers an elementary understanding of:
  • What are organic and inorganic pigments and dyes and where do they come from
  • The relationship between pigments and dyes and lightfastness
  • ‘Old’ pigments still in use – and those which have been replaced
  • ‘New’ pigments created in the laboratories – and why they are a good thing
I can see this will take more than one post so first. I'm going to explain the basics about pigments and dyes today.

What are pigments and dyes? (Definitions)

What is pigment and what is a dye? How does a pigment differ from a dye?

At a basic level:
  • pigments
    • do not dissolve in water and may be opaque.
    • Even when ground down, particle sizes are much larger than a water molecule.
    • Pigments are used by artists.
  • dyes
    • dissolve in water,
    • are always transparent and
    • can bind permanently to all porous materials.
    • Dyes are mostly used in industry.
Here are some different definitions that I've collected.
A pigment is a material that changes the color of light it reflects as the result of selective color absorption.......permanence and stability are desirable properties. Pigments that are not permanent are called fugitive. Fugitive pigments fade over time, or with exposure to light, while some eventually blacken.
Wikipedia - pigment

The colouring agent in drawing and painting media. originally from natural plant and mineral sources, most pigments are now synthentic. Pigment also refers tp pure colour in powder form
Artists Colour Manual"

Pigments are powders that are in a binder such as acrylic or oil which covers or adheres to a surface.
"Colour"

pigment noun 1 any insoluble colouring matter that is used in suspension in water, oil or other liquids to give colour to paint, paper, etc. Compare dye. 2 a coloured substance that occurs naturally in living tissues, eg the red blood pigment haemoglobin, or chlorophyll in the leaves of green plants. verb (pigmented, pigmenting) to colour something with pigment; to dye or stain. pigmentary or pigmented adj.
ETYMOLOGY: 14c: from Latin pigmentum, from pigere or pingere to paint.
Chambers Dictionary
You use dyes to dye to produce a dyed colour! Confused? See below for an explanation....
dye verb (dyed, dyeing) tr & intr to colour or stain something, or undergo colouring or staining often permanently. noun 1 a coloured substance, either natural or synthetic, that is used in solution to impart colour to another material, eg paper, textiles, leather, hair. Compare pigment. 2 the solution used for dyeing. 3 the colour produced by dyeing. dyable or dyeable adj. dyer noun someone who dyes cloth, etc, especially as a business.
ETYMOLOGY: Anglo-Saxon deagian.
Chambers Dictionary

Dye: A colouring agent that dissolves in water, used for colouring fabrics. Dyes are also used to colour white powder to produc 'pigment lakes' and 'pinks'. .....
Lake: The pigment colour produced by dyeing a white inorganic material such as gypsum or chalk with organi colouring matter through the use of a mordant
"Artists Colour Manual"

Dyes are pigments that are dissolved and absorbed in a fluid
"Colour"
Organic and Inorganic; natural and synthetic

Pigments are either organic or inorganic. This means whether or not the molecules contain carbon - organic pigments contain carbon.

This historical differentiation was based on a notion that organic means coming from things which were living and inorganic means it wasn't synthesized from a life force.

Today, there is a more defined separation between what is natural (from a living organism); what is synthetic (manufactured through a chemical process) and what is inorganic (not from a life force)

Rubia Tinctorum - Common Madder
Wikimedia

Today there are:
  • natural organic pigments/dyes - these are pigments/dyes extracted from natural (animal and vegetable) sources and living organisms e.g. derivatives of madder or cochineal. They are chopped, ground, boiled and dried to extract the pigment powders. They have a tendency to fade.
  • synthetic organic pigments/dyes - these are pigments/dyes that are manufactured as organic compounds e.g. alizarin crimson (a synthetic replacement for madder) and all the quinacridone colours (which are organic compounds and include the modern synthetic replacement for alizarin crimson because of concerns about the latter's weaknesses in relation to colour fastness)
  • inorganic pigments/dyes - these are derived from naturally occurring earth colours (eg ochres and iron oxides ), metal compounds, minerals (e.g. cobalt) and clays.
I'm still trying to find a website which defines all colours by whether they are organic or inorganic, natural or synthetic.
There are a number of other websites which provide excellent information about pigments - for example
How do pigments behave?

Not all pigments behave in the same way e.g. pigments can dry at different rates. Consequently it is worth trying to understand a little bit more about the characteristics of different pigments. (This is different from understanding the difference between different paints.)

The basic characteristics of a pigment vary as to:
  • colour bias
  • granulation/dispersion /sedimentation (try the Handprint sedimentation test )
  • toxicity
  • tinting strength
  • staining and bleeding
  • transparency or opacity
  • Resistance to alkalis and acids
  • Reactions and interactions between pigments
  • drying rate
  • lightfastness
Binders and other ingredients in art media

More from Arcobaleno Pigmenti de Nube Massimo - the pigment shop in Venice (see Venice - a resource for artists for a map of where it is)
copyright Katherine Tyrrell

Differences between media and between different brands of one medium are significantly influenced by the different formulae used by different manufacturers and the extent to which they vary substances used to bind the pigment into the medium.

Pigments are used for coloring paint, ink, plastic, fabric, cosmetics, food and other materials. Most pigments used in manufacturing and the visual arts are dry colourants, usually ground into a fine powder. This powder is added to a vehicle (or matrix), a relatively neutral or colorless material that acts as a binder.
Wikipedia - pigment
Art media normally start with two principal ingredients:
  • colourant, commonly pigment (organic or inorganic);
  • binder, the substance that holds the pigment in suspension and fixes the pigment to the painting surface
Some media, most often paint, also includes or needs to be combined with two more ingredients:
  • additives, substances that alter the viscosity, hiding, durability or color of the pigment and vehicle mixture; and
  • solvent, the substance used to thin or dilute the paint for application and that evaporates when the paint hardens or dries.

The main reasons why people like a particular art medium are due to:

  • quality of the pigment used (eg how finely it is ground - is it gritty or not?)
  • the nature of the binders and additives used (eg how well the paint flows or gives up its pigment)
  • the ratio of binders and fillers to pigment (the pigment load)
The binders and fillers added to pigments vary in terms of how they affect, for example, the saturation or lightness of a colour. Each has its own unique way of reflecting or absorbing colour and thus determine the final spectrum of colour available. Binders surround pigment particles and control how the pigment reacts to light and the environment. The nature of the pigment can dictate which binder produces the best result.
  • Dry binders include: wax, oil, clay/kaolin, graphite (Carbon mixed with clay)
  • Liquid binders include: water, egg yolk+water, liquid, linseed oil, beeswax, acrylic polymer, gum arabic, oil, milk-derived polymer, powdered glass.
Using high quality materials slows down the response to atmospheric conditions.

I'm aiming to produce a chart at some point showing how binders combine with pigments to produce different art media.

Permanence and lightfastness

In the last 200 years, the range of pigments and colours has increased but, more importantly, so has the lightfastness. This will be covered when I look at the classification of colour.

Colourmen

Prior to the advent of tube paint, most paints were made up by people called Colourmen who sold premixed paint in pigs bladders.

Pere Tanguey, painted three times by Van Gogh (see right), was one such colourman who supplied a number of painters in Paris at the end of the nineteenth century.

This is a link to the Winsor & Newton Colourman's Manuscript Archive Project: Page-Image Database of Historic Recipes for Paint Making

LEARNING POINTS

I've decided it might be useful to try and summarise what can be concluded from the overview

  • all colours come from pigments or dyes;
  • pigments and dyes come from a number of different sources
  • a pigment is a material which can provide colour but which does not dissolve in water
  • a dye is a pigment ground down to very fine particles which can impart colour when suspended in a solution or medium
  • pigments do not all behave in the same way - because they come from different sources
  • what makes paint vary can be the nature of the pigment - but it can also be the binder or filler used to make the medium. In other words it's not just about the pigment load.
Tomorrow - more about the art materials perspective on colour.

Bibliography:
Links:

The Making A Mark Project on Colour - previous posts
Resources for Artists information sites created by makingamark
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