Digital BW, The Print

Steadman,

Just a couple of comments. I think that the receiver coatings on the 
inkjet papers are more than just calcium carbonate (I think this is 
added in the paper itself as the pH buffer) and involve organic 
components which ultimately may be the weakest link in the chain.

Second, the goal in fresco is to wind up with the pigments sealed in 
the substrate under a coating. Which comes back to the idea of 
coating for maximum longevity.

Martin


--- In DigitalBlackandWhiteThePrint@y..., "Steadman Uhlich" 
<steadmanuhlich@k...> wrote:
> Greetings Digital Printmakers.  (cross posted)
> 
> There has been much discussion on this forum about the interactions 
of inks, pigments and paper coatings (which are usually a form of 
calcium carbonate).  While responding to another forum post on the 
issue of color pigments interacting with the substrate, my old fuzzy 
brain cells synapsed with a spark that flashed to old Michelangelo 
and his problems with his fresco work in the Sistine Chapel.  
> 
> I am posting this excerpt below in the hope that you will gain some 
smile from knowing that artists (and a master like Michelangelo) 
struggled with the media of their times, struggled with longevity 
issues, struggled with pigments and substrates, etc... Read the last 
few lines about fresco secco.  
> 
> Perhaps this post will encourage you to "not give up" and remember 
that lowly pigments and calcium can last a long time.  And just think 
what Michelangelo would be doing with an Inkjet!
> 
> Regards to all, 
> 
> Steadman
> 
> The following is copied from the Encarta Encyclopedia on the Web: 
> 
> Pigment is applied to the top layer of several layers of plaster 
for a buon fresco. The painter usually applies to the next-to-last 
plaster surface a sketch, or cartoon, of the painting. 
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> The outlines of the various figures and forms of the cartoon are 
then reinforced with dark watercolor. Plaster is laid over the 
drawing in small sections, and color is applied to the wet plaster, 
often aided by another sketch of the color scheme. As the plaster 
dries, the lime in the plaster reacts chemically with the carbon 
dioxide in the air to form calcium carbonate; this compound forms a 
film over the colors, which binds them to the plaster. This makes 
them part of its actual surface and also gives the colors an unusual 
clarity. The colors of a fresco are usually thin, transparent, and 
light, often with a chalky look. In the Renaissance, methods were 
found to give the colors somewhat more opacity.
> 
> In buon fresco, the painting must be done quickly and confined to 
essentials. The artist must know precisely how much watercolor the 
plaster will absorb. Too much paint causes the surface to 
become "rotten." Cutting away the defective portion, laying on fresh 
plaster, and repainting is then necessary.
> 
> In fresco secco, the dry plaster is rubbed with pumice stone to 
remove the crust, then washed with a thin mixture of water and lime. 
The colors are applied on this surface. The effect of fresco secco is 
inferior to true fresco; the colors are not as clear, and the 
painting is less durable.
> 
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