The short answer: the iron is too cool, moving too fast, or pressing too lightly. Beads need steady medium heat with slow, pressing circles, ten seconds or more on the same spot.
When beads come off the board still loose, ninety percent of the time it is the ironing technique, not the beads. The plastic needs to reach its melting temperature and stay there long enough for the outer skin of each bead to flow together.
Check these in order
- Heat: set the iron to medium, around 140-160°C (285-320°F), and let it warm up fully before starting.
- Speed: iron in slow circles over each area, not quick back-and-forth passes.
- Pressure: press down with firm, steady pressure so the iron sinks toward the pegboard.
- Time: ten seconds on the first pass, then flip and repeat on the other side.
- Paper: use thin parchment paper. Thick paper or folded paper blocks heat.
One more culprit: a steam iron. Even on dry mode, residual steam in the iron cools the soleplate. Empty the water tank and run the iron empty for a minute before you start. For more on ironing basics, see our complete ironing guide, and pick up tools from our shop.