>But as I say, why not dextrine?
Because dextrine is a sugar, not a starch. Dextrine would dissolve in the
water, and mess up the action of the other ingredients. Then again, maybe
not. Note the following (from the Merck Index):
Dextrin [note there is no final "e" in the chemical name] is produced by the
dry heating of unmodified starches, as well as by controlled hydrolysis of
wet starch. [much tech info deleted here] Soluble in 3 parts boiling water
to a gummy solution; less soluble in cold water. USE: Excipient for dry
extracts and pills [in medical terminology - if I'm not insulting your
knowledge - "excipient" means "filler"]; for thickening dye pastes and
mordants used in printing fabrics; sizing paper and fabrics; preparing felt;
manufacturing printer's inks, glues and mucilage; polishing cereals; and in
matches, fireworks, and explosives.
So, though dextrin wouldn't be useful for preparing a matte finish, it might
be interesting to try it as a sizing material instead of gelatin! Anyone
have any dextrin to try?
The reason this hit me is that, as a stamp collector in another life, I
learned that the stuff they used to put as an adhesive on the back of stamps
was dextrin. Now they use synthetics. The dextrin adhesive had a sweet
taste. Times change.
Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net