One of the benefits of attending the NAMTA meeting is the presence of a lot of art material dealers. The subcommittee of ASTM that focuses on artists’s materials, designated as D01.57 creates manufacturing standards for art materials. Most people wonder if the subcommittee is an advocate for artists. Directly, no we are not. Indirectly, we do provide some form of advocacy. We have artists who are members of the subcommittee and provide feedback to manufacturers about making quality art materials. However, at the end of the day, the primary work of the subcommittee is to create methods of testing an art material so that it qualifies for being of high quality because our tests are a metric for superior performance of art materials. Simply stated, the tests we devise gauge the light fastness, fineness of the grind of the pigment, proper labeling of products for both health/safety and pigment/vehicle content. For the general public, a manufacturing standard is pretty boring. It specifies how machines used to expose paints to high intensity lights should be set, how the samples for testing should be prepared, how to measure the samples with a spectrophotometer and how to determine the light fastness category of a product. Are you asleep yet?
A wonderful feature of having all the manufacturers at the NAMTA show is that we can host an ASTM D01.57 subcommittee meeting. It is one of the two annual meetings we must conduct to discuss standards. Standard making is a slow process for several reasons. First, nearly all of the subcommittee members have regular full-time employment that is the primary focus of our attention. Second, we spend a lot of time testing the tests we devise to assure everyone that they work properly. While labeling a product correctly is easy to accomplish, conducting a sound, reasonable light exposure test is far more difficult. The whole discipline of accelerated aging is filled with variables and complexities. Natural aging of an art material sample would take too long (50 to 150 years) to determine if a pigment fades so we have to shorten the time by accelerating the process. However, acceleration can cause anomalies to occur that would never display themselves if natural aging were conducted. It is possible to obtain results with accelerated aging of products by carefully researching how much light energy for a duration of time is required to yield an answer.
In future blogs, I will discuss small digestible segments of some areas of interest to artists regarding ASTM testing. While a lot of it is technical, some of the work we do has some level of interest to the artist. More importantly, some of the topics we have to tackle impact the overall quality that artist might assume is part of a product.
I will leave you with this thought. Art materials without standards written for them have NO means of being verified as to the light fastness of the product or the materials contained in them. Note, that ALL art materials sold in the USA are required to be screened for health hazards and labeled appropriately. But an art material with no standard attached to it provides no pressure by the manufacturer to reveal the contents of the pigment, binder or other additives that are contained in substantial quantity.
If you need an illustration of a medium that has no standard attached to it, look no further than PASTELS. Currently, without a standard, the artist is at the mercy of the manufacturer when it comes to producing products that are light fast or have colorants that are known to be superior performers. Do not misinterpret my thought. Most manufacturers try hard to make good quality pastels but without a good light fastness test, neither the manufacturer nor the artists really knows if the products produced are truly light fast. In a round robin test conducted by the ASTM D01.57 subcommittee several years ago, the test revealed that approximately 30% of the pastels tested failed to be of a suitable light fastness to be considered an artist grade, high quality product. If you had to guess what the composition of those pastels are, the ones that use dyes and the usual suspects that display bright high intensity hues (pinks, reds, violets) are the most likely to fail an ASTM art materials light fastness test.
We are working toward creating a robust light fastness and labeling standard for pastels at the moment. The most important factor in establishing and using a pastel standard comes from the artist. If pastel painters demand that their favorite supplier of pastels conform to an ASTM test for pastels, it should provide the energy to convince pastel manufacturers to test products, take the results of those tests, identify inferior, fugitive colors and come up with replacement hues that pass the light fastness test. Once, done, they can proudly show off their ASTM conformance to the pastel standard and assure customers that the pastels they make use light fast pigments.
We will return to this subject later.
Grammar of Color 