It's cyanotype on fabric, using the same chemistry. Barbara Hewitt at
Blueprint/Printables can tell you more about how she deals with the
variables. She has an 800 number: (800) 356-0445
Patrick Hilferty
**************************************************
Patrick Hilferty
Belmont, CA 94002
E-Mail: philferty@earthlink.net
Web Page: http://home.earthlink.net/~philferty/
**************************************************