Methyl cellulose problem?
- I have just gotten started learning marbling, practicing a little on paper although my intention ultimately is to do my marbling on wooden objects. I decided to use methyl cellulose, made up a batch months ago, dabbled very little with some unsatisfactory acrylic paints but had none of the problems I have now. Having gotten my interest up again, I made a new batch of size exactly measured, added ammonia as per instructions (although I don't recall having added ammonia to the first batch) and was surprised to find this new batch a lot less viscous than the first. I changed paints to Ceramcoat, which for the first time have not failed me with sinking promptly as the others did, but unlike the old paints, these seem to badly discolor the size after only very little use. Although I am getting better prints by far than I did months ago, something still seems to be wrong with the size, just not supporting my paints the way I think it should. After doing only two prints this afternoon, the size was a muddy, dark purple and I almost declined to pour it back in the stock bottle. As I came to the bottom of the tray, there was a lot of pigment indicating clearly that a lot of my paint is still sinking. I did skim the darkened size with a strip of alum paper and no pigment came off, so it may be that I am concerned about nothing,, but I would much appreciate anyone who can either reassure me that all is well or tell me what is wrong.
A most helpful expert I have solicited help from uses only carrageenan and hence can offer nothing very specific about my methyl cellulose, but she did mention that she thought there was a consideration about pH with this size. To somewhat further reduce the variables, I skim immediately before applying paint, touch the paint very gently to the surface from squeeze bottles, use distilled water in my size, maipulate the paint surface to a minimum, blowing a little briefly but not flogging the surface. Room temperature is not great, probably mid sixties, not more. Can any of you all shed some light?
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