Dwight
It depends upon the format you will be using. If it is medium or 35mm I
suggest that you shoot as if you were going to print onto silver gelatine
and increase the contrast at the interpositive and interneg stages.
For larger formats if you are going to contact print from the negs, use FP4
rated at 32 and develop in Ilford Universal developer. I m 45 s should give
you a good neg for cyanotype with a density range of about 1.4.
Terry