Hello. I have been asked if the popular salt technique in watercolour painting causes damage to the paper. The method involves dropping fine or coarse table salt on wet watercolour paint to remove spots of paint by absorbing it. When the painting is dry, the salt is brushed off leaving speckles of white paper. It is not a new technique, it has been used for decades.
Does anyone know if the residual salt in the paper poses a risk of degredation?
I checked the forum and couldn’t find anything covering this topic.
Thank you Gillian and Margaret, very helpful!
Hi
I have forwarded your question to our paper conservation moderators.
Hi! I don’t believe salt would necessarily cause any issues for your work; sodium chloride has a pH of 7, which means it is fairly neutral. The salt crystals themselves could cause damage to the paper fibers if they are rubbed in to the paper, or otherwise abrade the surface. You might find that the areas with salt respond differently to moisture if the piece becomes wet, but at that point you would have other issues! One thing to note – if you’re buying table salt, make sure it hasn’t been fortified with iodine, as that could cause unpredictable results.
Gillian
As always, it’s all relative. A paper saturated with dissolved table salt would likely have problems in elevated humidity which encourages salt recrystallization accompanied by mechanical stresses. However, the amount of salt actually absorbed by the paper from localized sprinklings onto wet watercolors is not likely to be great. The fact that individual salt crystals remain to be brushed away indicates little actual dissolution.
Margaret Holben Ellis
New York University/The Morgan Library & Museum
