Common issues that can arise when applying icing sheets or wafer paper to cupcake toppers:

1. Wrinkles or air bubbles: If the icing sheet or wafer paper is not applied smoothly to the topper, it can cause wrinkles or air bubbles to form. This can be caused by not moistening the topper enough or by not smoothing out the sheet carefully.
2. Peeling or curling: If the icing sheet or wafer paper is not applied firmly to the topper, it can peel or curl up at the edges. This can be caused by not allowing the topper to dry completely before applying the sheet or by using too much moisture when applying the sheet.
3. Smudging or smearing: If the icing sheet or wafer paper comes into contact with moisture or oil, it can smudge or smear, causing the image or design to become distorted. This can be avoided by ensuring that the topper is dry and free of moisture or oil before applying the sheet.
4. Fading or discoloration: Over time, icing sheets and wafer paper can fade or discolor, especially if they are exposed to light or heat. To prevent this from occurring, store the sheets in a cool, dry place away from direct sunlight and moisture.

By understanding and addressing these common issues, you can improve the quality of your cupcake toppers and create professional-looking results.