I know the wrinkles you're talking about. These are not the typical "bubbles" that form, these are the type you get with MK when you iron down a wrinkle. Now you have MK stuck to MK, which is a double whammy. MK doesn't shrink very well, and it's adhesive is permanent. So when you get one of these, you're stuck with it for life.

That's why I use UltraCote (Hold up the product Spokes-Model).

When you get one of these types of wrinkles, a heat gun will take it out even if it has been ironed down. The first time I saw that I was SOLD!