Not ignorant at all. Ethyl alcohol is the stuff you drink. Denatured alcohol
has various chemicals in it to make it undrinkable, but also might make it
unsuitable for photographic processes - you can try, but it's not what I do.
I go to my friendly liquor store and buy 180 proof alcohol which is about
90% ethyl alcohol with the other 10% water. When you're finished using it
for photography, you can use it as a mixer, like vodka. (Russian vodka is
about 50% ethyl alcohol, usually without anything else but water; you can
use it as ethyl alcohol, because it's just a diluted form. I'd try getting
the pure alcohol if you're using it in a solution that has no water.) You
probably can also get pure alcohol at the pharmacy, but the cost is prohibitive.
Have fun.
Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net