The idea is to make "lamp shades, hall lamps, screens, conservatory
windows, etc."
Instructions are to size a piece of parchment or tracing paper with
arrowroot, then sensitize with "citrate of iron and ammonia" and "Potass
ferricyanide," place the parchment under pressure before it's totally dry
(under glass) so it doesn't curl up,and expose. Since the picture will be
viewed by transmitted light, "printing should be carried to a good depth."
I infer, BTW, that this formula used brown scales, because Swinden tells us
"when ready for use the parchment should be of a pale orange color." (Well
he really said "colour," but never mind.)
After washing, he says "colour may be considerably improved & the image
intensified by passing the print through a solution of [water & HCL]."
Since this is not so, & his other formulas for "variations in colours"
are an uncertain lot (including "lilac" from ammonia), I doubt his black
formula, but in case Mike Ware is reading this, he says for black cyanotype:
"Place for a few minutes in a 2% solution of carbonate of soda, until
black; remove, wash thoroughly and immerse in a 10% solution of
sulphuret of copper, til the print assumes a rich black tint. Remember
that prints must be washed thoroughly after immersion in any of the above
liquids."
Before mounting transparencies on glass, soak in weak solution hot
gelatine and squeegee to their supports. Not only are they "suitable for
decorative purposes, but they will be found useful in stopping up glass
doors and windows having objectionable outlooks."
I know a few people with objectionable outlooks could maybe be stopped up
at the same time, but it occurs to me that some of those cyanotype toning
formulas that don't work (the violet, the intensification, etc.) *DID*
work with the formula made from brown scales?
Judy