What goes wrong with fuse beads, and the fix
Curling, holes closing up, beads that will not stick, colours that go dull — each has one cause.
The piece curls. Cause: it was lifted or moved while still warm. Fix: after ironing, leave it flat under a book for a minute. If it has already curled and cooled, iron it again briefly and then cool it under weight — this works, but only once or twice before the beads over-melt.
The holes have disappeared and the colours look dull and milky. Cause: too much heat or too long, and it is the one mistake with no way back. Prevention is the only fix: stop when about three quarters of the rings have closed, not when all of them have.
Beads come away when you lift the paper. Cause: not enough heat, or an iron that had not reached temperature. Fix: put it straight back under the iron. Under-melted is always recoverable; this is why stopping early is the safe error to make.
The middle is fused and the edges are loose. Cause: the iron was held still over the centre instead of moved. Fix: small circles, out to and slightly past the edges of the picture. The corners of a square piece need a moment longer than the middle, not less.
White fibres are stuck all over the surface. Cause: ordinary paper instead of baking paper or glassine. There is no clean fix — picking them out with tweezers takes longer than the piece did. Check the paper before the iron goes on.
Brown scorch marks in patches. Cause: aluminium foil, or an iron on the linen setting. The plastic is burnt, not just melted, and the marks are permanent. Drop the temperature a full setting and try again on a scrap.
The whole board tipped before ironing. Fix: lay it flat immediately rather than standing it up to inspect it, and lift the loose beads off the surface before they roll into the pegs that are still filled. Then rebuild from the pattern — this is where working colour by colour pays for itself.
The finished colours do not match the pattern on screen. Cause: screens emit light and beads reflect it, and no conversion between the two is exact. This is why the colour list gives manufacturer codes rather than colour names — buy by code, and check the code against a bead you already own before ordering a whole tub.