Before contracting a professional wallpaper installer request for specific experience with self adhesive and peel and stick wallpaper. If possible consult them prior purchase about your project and the materials you want to acquire. Provide them with samples if possible. Check yourself for overall merchandise quality before installation: pattern repeat, overlap and material stability before handing it to your installer (take pictures). Ask your installer to make the same quality check before starting. Make sure they read carefully the instructions included with the order and supervise they are being followed. If possible supervise closely the entire project.
Sometimes the wall has slight deformations such as bumps or depressions we do not see with plain eye but come out during a wallpaper installation. When the wall has a deformation the wallpaper does not match in some areas even when everything was checked out before hanging it. If this happens to you there is no solution for it more that try to cope with it or abort installation. Never pull and try to force the material in place. In our experience when this happens you need to place the wallpaper to match at it’s best without pulling and keep installing the rest of the panels, this issues usually happens in small areas of the wall and once the install is finished you will not notice it in the overall project. We do an extensive quality control for each order before sending it your way but always inspect your wallpaper match or repeat before starting the installation. Lay your panels on the floor and align them, this is an opportunity to check that everything is ok before starting the install. If you run into any issue while installing you will be able to determine more accurately the issue.