Using natural soil pigments on paper?ApproveRejectUn-ApproveSubscribeUn-Unsubscribe
Question asked 2019-01-24 06:06:43 ...
Most recent comment 2019-07-19 15:19:32
Dear MITRA Moderators,
I want to create a three-layered paper piece based on the element of Earth. I'm doing a four-piece suite, one for each element, and am involving each element directly (for fire, I burned the edges of the paper), etc.
I'm using a 300 lb paper for the first layer, and would like to use natural pigments including clay soil. I'll adhere a second layer (140lb paper) to the first with a brayer, using a product recommended to me by the art supply representative (Daniel Smith Transparent Watercolor Ground). I'd like to use natural pigments here, including clay soil and a homemade walnut stain. For the final paper layer, I'll adhere a thinner paper (I think it's 90 lb) and use watercolor pencils. I plan to distress the first and second paper layers respectively to expose the pigment underneath.
Does this sound like a sound approach? Can you use regular clay from a yard or creek? Is homemade walnut stain ok to use, or would it be too acidic, etc?
Many thanks! I'm really excited about this project!
Answers and Comments
Regarding the clay, it depends on where you live and what portion of the clay is organic matter which might break down. Some soil has a lovely color when freshly dug due to plant material, but the organic components might not prove durable. Clay that is stained with oxides and ochres will be more reliable over time. As far as the walnut ink is concerned, any vegetable-derived colorant can be vulnerable to color change from exposure to UV light (though anyone who has hulled black walnuts may find it difficult to believe that the stain will ever fade willingly). If I were offering such a piece as you are describing to a collector, I would suggest display under protective glazing, out of direct sunlight or intense illumination, and recommend that the piece be stored at intervals, to reduce total exposure. This is really good advice in general for watercolors where some pigments are not of the highest lightfastness.
I'm afraid I can't even hazard a guess about boiling or otherwise refining clay. I like your idea about using pigments from terrestrial (mined) sources. Some historical colors have gone extinct as mines have become played out, (the original Venetian Red, Caledonian Brown, Cappagh Brown, and some other ochres were mined until the source was exhausted) but there are still some really great pigments that are not synthetic.
The salt will remain reactive to changes in RH but really,
your piece should be stored in a stable environment anyway. I have seen many
works where there are effects that had to been created using rock salt and they
at least initially appeared in fine condition but that is not a good test for
future longevity. I would think that it would be good to brush off what you can
before framing etc. I will ask a paper conservator to comment on what NaCl does
There are a couple of transparent watercolor
grounds on the market. I have to admit that I do not know what such a ground
would be composed of. I am assuming it is some transparent filler like fumed
silica or glass platelets etc., leanly bound in an acrylic or PVA dispersion. Without
more info, I cannot really comment. Perhaps others here have a greater
knowledge of these grounds.
If you are using a watercolor ground as a wet adhesive to stick paper to paper, if the ground is acrylic-based, it will likely work. A simple adhesion test conducted using scrap paper will reveal whether it will bond strongly enough. Gloss acrylic mediums are usually the best adhesives. Matting agents like the ones Brian listed as possible ingredients interfere with some of the like-to-like adhesiveness of acrylic products, but if the ground will stick permanently to one sheet ofpaper, it should stick two pieces together.
this for Joan Irving Senior Paper Conservator of Winterthur Museum &
Affiliated Associate Professor of the Winterthur and University of Delaware Art
Conservation Program. This really is a very good question – and I can’t recall
anything in the conservation literature about this topic. As we
discussed, the main problems with the NaCl might be more theoretical than
actual. If the watercolors are kept in a stable environment and in acid-free
enclosures (mats, folders), they will probably be fine. Theoretically, the
hygroscopic nature of the salt could raise the moisture content of the paper
(with potential for foxing, mold, etc.). The other theoretical downside would
be possible disassociation of the Cl ions, which could yield degradation
products such as hydrochloric acid. However, most watercolor papers are really
robust – generally quite thick and very well sized; sizing provides lots of
chemi-mechanical protection and reduces the porosity and susceptibility of the
paper to atmospheric pollutants, moisture, mold, etc.
So, if any paper
could tolerate common sodium chloride – it would be a well-sized, rag,
watercolor paper. It would be helpful to mat these objects in good quality, 4
or 8-ply, alkaline, 100% rag boards with zeolites (which are desiccants as well
as good scavengers for atmospheric pollutants).
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