Viewing Topic "Cure Time for Tempera Ground"
We will send panels by the end of March to reach you in the first week of April.
Thanks - all helpful information, George. I'd be happy to try out the new panels - I'd also love to show them to my students, my first workshop is in mid-April, so if you could send me a sample in the beginning of April that would be great.
We advise waiting three days for all water to evaporate from the ground. Since the ground does not contain coalescent solvents, the ground polymerizes rapidly. We do not advise using heat to cure the ground, but light is helpful, though no direct sunlight due to UV light. The ground is water-insoluble as soon as water completely evporates, and the ground has relatively good scrub resistance, but not as good as acrylic grounds. We will be conducting more tests of the ground over the next few months to better answer these questions.
We have produced ACM panels with tempera grounds and plan to offer these to artists next month. Michael Bergt and Fred Wessel tested them and found them useful. We will send you some samples when you return home.
Me again. Please ignore the birthday greetings at the top of the previous question. When I pasted it from another document onto the Forum I inadvertently included a note to my sister that was on the same document. Sigh, the silly things computers sometimes have us do...
I've been developing metalpoint drawings atop Natural Pigments Tempera Ground - it works well and I like the convenience. My method is to develop a drawing with metalpoint - then, when the image is nearly complete, apply a very thin scumble of the Tempera Ground over the entire drawing. It doesn’t obscure the image, it’s more like a transparent mist or veil that compresses the value range, softens transitions, adds atmosphere. It also adds a fresh layer of abrasiveness, so I can go back in with metalpoint and deepen the darks. Again I develop the drawing with metalpoint; then once again, when it’s nearly complete, I scumble a thin layer of Tempera Ground on top. I do this many times, alternating from metalpoint drawing to thin scumbles of Tempera Ground, up to a dozen layers until the drawing has the values and atmosphere I'm looking for.
At what point (time-wise) does the Tempera Ground become less vulnerable to abrasion (less affected by the scritch scratch of a metalpoint tip), and less vulnerable to wetting (i.e. if I paint egg tempera on top)?
In other words, what is the cure time for the Tempera Ground? Does either heat or sunlight speed up the cure time? And once cured, is it water insoluble?