Blisters or air bubbles sometimes appear when there is too much tension on the fabric. To help fix this problem, pull your Squid away from the window until there are no air bubbles left. Then stick your Squid to the window again with as little tension as possible. If this doesn't work, you can completely remove the fabric from your window and reinstall. Make sure your window is free of dust and grease and press Squid firmly to the window. The glue is pressure sensitive.