>Again this time I noticed no increase in Dmax over my old formula.
My test prints were fairly weak to begin with but I used the old trick of
adding on capful (approx 15 ml) of 3% household hydrogen peroxide to a liter
of water and putting the print into this for a few seconds. It immediately
goes dark blue. I noticed that as they dry they also will darken but the
hydrogen peroxide seems to greatly improve the dmax. I don't have much in
the way of traditonal blueprints to compare, but I do think the blues are
much much better in Ware's formual than in the traditional. I was teaching a
class with Meridel Rubenstein at the American Institute of Indian Arts
(IAIA) here in Santa Fe and some of our class had done blueprints in the
previous semester, and they were pretty anemic compared to this stuff.
I also went through three batches of grinding by hand before I got it right.
Those first mixes were not too exciting. I think that if you do not do it
precisely as Mike says, the stuff is not going to work well. Because we are
making batches for sale, I can't just sit around and grind it by hand in a
mortar and pestle. I use a 2 liter high powered restaurant grade blender to
first grind the ferricyanide to a light yellow, and then to mix it with the
ammonium ferric oxlate. We then vacuum filter it after it sits for a few
hours. This seems to work better than hand grinding. You can also use a
$30.00 household grade blender but the problem is you will need to start
with at least 150 grams of pot. ferricyanide in order for it to grind
properly. I needn't have to remind people that your blender is now dedicated
exclusively for lab work.
Dick
My guess is that the preparation is not as precise and it should be.
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