Sonntag, 26. Februar 2012

The influence of water hardness

Every time I´d dryed perfect exposed wet fabric-cyanotypes in the past, I wondered about the fact, that they bleached out very strongly with yellow stained highlights. Sometimes this goes with the picture but often it was to strongly fade out. On paper this was only minimal detectable and therefore never a problem.

You must know, our tap water is very hard, >180 ppm, so I went into preamble, that the large amount of remain water in the fabric leads into a chalk enrichment during the drying process. And we know all, alkalinity is the cyanotypes death.

Confused by those poor results on fabric I have done a comparative test under identical conditions last week. The first cyanotype was washed out 2 times á 5 minutes in tap water and third wash á 5 min was done in destilled water, the second cyantype was washed out 3 times á 5 minutes in tap water before dryed. After the drying process the result was very surprising for me!

See yourself, the left cyanotype washed with destilled water, the right cyanotype with tap water, Beside that, on this picture the fade out effect fits well, the result isn´t so bad.

© Andreas Reh     Cyanotype on Canvas, 42x48cm, the left cyano washed in destilled water, the right cyanotype in tap water.