Hi Stephanie,
The adhesive on the Velcro dots is made to cope with high temperatures, but it does work best when the surface is carefully prepared and the dots are applied to the right area. Even when frames look clean, they can still carry a very light, invisible residue from cleaning products, polish, silicone, dust, or skin oils, which can affect how well the adhesive bonds.
That’s why we mention this on our website — it really does make a difference. For the most reliable, long-lasting hold, we recommend giving the surface a quick wipe with isopropyl alcohol and then pressing the dots firmly into place. If those steps are missed, the adhesive may not fully bond and the dots can sometimes come away over time.