RE: First Tricolor Gum (on aluminum)
My understanding also is the same, CaCO3 gives a gritty/toothy surface. Probably matte acrylic gesso also contains considerable amnt. of CaCO3 both as a colorant and as a surface tooth agent. Since I learned this from Keith and I also know that he may put 6 - 7 layers on top of each other, I'd say this kind of surface priming is pretty robust. The layer order is Cyan, Magenta and Yellow... (Black is missing - didn't bother since the M layer was unregistered, I just wanted to see how colors interact with each other.) Regards, Loris. -----Original Message----- From: Katharine Thayer [mailto:kthayer@pacifier.com] Sent: 11 Aralık 2006 Pazartesi 17:07 To: alt-photo-process-l@usask.ca Subject: Re: First Tricolor Gum (on aluminum) ... The calcium carbonate, I take it, is for "traction" to give the gum something to hang onto, much like the fine sand I use in acrylic for the same purpose on hard surfaces. I find that it doesn't always hold three layers; sometimes it will, but sometimes the top one will only hold in areas where there aren't already two layers of gum. And sometimes the top layer will stick to the other two layers and then all three layers pull off the surface together. So I'd say you did quite well on your first attempt. Which was your last layer, the yellow or the magenta? I suppose in a way this could be seen as a variation on the gelatin/ gesso thing. It's interesting to watch how ideas spread and mutate. Katharine
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