Darkroom Variables with Classic Cyanotype – Waiting time from coating to printing.

  • I coated a sheet of paper using a rod and very little emulsion (0,0025 ml/cm2) down to where I drew the pencil lines. I cut the sheet in four strips when dry. 
  • Room temperature was 22 deg C and Relative Humidity 74%. 
  • I waited 20 minutes from coating and printed the first quarter of the coated sheet (Test strip 415c) for 1 minute (a shorter exposure time than my standard so to better see any color variation when comparing it with the other prints). 
  • I covered a part of the coating with an opaque material to have a non exposed area where to check fogging.
  • I waited 40 minutes from coating before printing the second quarter of the sheet as above (Test strip 416c).
  • I waited 60 minutes from coating for the third quarter as above (Test strip 418c).
  • I waited 80 minutes from coating for the fourth quarter as above (Test strip 417c).

P.S. yes I mismatched the strips already numbered when printing so they are not in sequence, but correct.

At the end of the test I could see there was no difference in dMax (color density) in the four prints and the fog under the covered part was pretty similar and almost absent.

In my conclusions there is not much difference if you wait for 20 or 80 minutes to print after coating. 

P.P.S.  I always suggest not to wait too long from coating to printing otherwise fogging may become evident in some circumstances (depending on quantity of emulsion used and R.H. of your place) and your paper white may be less white, or gone. 

I tend to always wait from 45 to 60 min for consistency in my darkroom variables, the base for a perfect digital negative.

This is an external resource for cyanotype printing of the Digital Negative video course. You can read more about it clicking HERE.