Do I need to block amigurumi?

Blocking works by forcing damp fibre into a shape and letting it dry there. A stuffed sphere is already being forced into a shape by the stuffing, and it is being forced harder than any pin could manage. Add water and you risk felting acrylic, distorting the stuffing and leaving water marks on cotton.

The one exception is cotton amigurumi that has gone slightly lopsided. Mist it heavily, reshape it by hand for a full minute, and let it dry away from heat. Cotton has enough fibre memory to hold a 3-4% correction.

Block the flat pieces before you assemble: ears, wings, fins, flat bases, blanket squares, and anything that has to be a specific measurement. Pin them out to the target measurement on a foam mat, mist until damp but not dripping, and leave 12-24 hours.

Steam is faster and riskier. Hold the iron 2 cm above the fabric and let the steam pass through it; touch acrylic with a hot iron and it will melt into a flat, shiny patch that cannot be fixed. Cotton and wool tolerate direct steam much better.

Dry flat, away from direct sun and radiators, with air moving. A fan on low is better than heat. Cotton at DK weight takes about 18 hours to dry fully pinned out; if you unpin at 12 hours the edges creep back and you have done the work for nothing.

Never hang a wet blocked piece. The weight of the water pulls the shape out at the top and you get a piece that is wide at the bottom and narrow at the top — worse than unblocked.