Other issues to watch out for when food, wax, etc. is attached to the part where there is no letters, numbers, etc.
Is One Allowed to Take Out the קידוש לבנה Cards Before Maariv?;
The 5 conditions which have to be met in order to fold the garment on Shabbos;
More Information About Playing Kugaluch on Shabbos. Fruit That Spilled Out of a Basket in the House;