So the paper expands, otherwise the paper will expand on the wall because there is a lot of water in clear paste, then your seam will open up. Personally, I dry hang with clay because there is much less water in it without pre moistening the material. There is much less water in clay paste and also water can not escape easily behind foil. It’s non porous.
The water is for expansion. It permits the non woven backing to “grow” 1/4” on the table so that you can “dry” hang it onto a pasted wall to avoid the weight of carrying it to the wall with paste on the back of it. Subscribe to my wallpaper channel and lean all these things.
