Why do seams shrink?
A lot of time could be spent on this question and we would still not cover everything. What I can tell you is that many times seam shrinkage is caused by the over application of wallpaper adhesive. Many paperhangers think that more is more when they should be thinking that less is more. Another cause of seam shrinkage is improper booking time of wallpaper sheets. Unfortunately the proper booking time is determined by material and adhesive type and this is an area of expertise that requires some years of experience. Another common cause of seam shrinkage is when a wallpaper installer rolls the seams too soon. This early rolling action forces paste away from the seams because the paste is still viscous and squeezes out from the seam area. You should wait at least 2 hours before attempting to roll seams, many times more than 2 hours.
