I'm enclosing a small jpeg file that illustrates a surprise I 
experienced.  
One of my favorite developers is pyrocatechin, which produces a very 
brown negative.  Since I have no darkroom just now, it is very tempting - 
and has become very common for me - to scan direct from my negatives 
rather than from prints.  I thought it would be interesting to scan the 
brown negative in color.  The enclosed file shows what the negative 
looked like and what I got when I simply inverted the map, making it 
positive.
I have never printed this negative in cyanotype, but it might be kinda 
cool.
Yours,
Cyano de Bergerac