This type of problem is normally an adhesion issue and the most common cause is 'drying-in' of the adhesive at the edge of the paper. When wallpaper is folded adhesive side in, the only area that is exposed to the atmosphere during the soaking period is the very edge of the sheet and it is this area that starts to dry out first. It is therefore important that an adequate amount of adhesive is applied particularly to the edges. The use of a seam roller may prove beneficial in such circumstances but be careful not to damage the surface of the wallpaper.
