For children with certain conditions, hospitals will fit them with a resting hand splint. They must form to the child's hand very specifically for maximum comfort, must breath, and must be light.
Thermoplastic usually performs at least a few of these requirements well. However sheets of the plastic lack holes for ventilation. The other problem is, for Bangkok-based Queen Sirikit National Institute of Child Health (QSNICH), reliable thermoplastic suppliers offer sheets that are very expensive, perhaps 4,000-5,000 THB (115-140 USD) a piece and might make between 5-10 splints each.
We started by tracing a volunteer's hand and 2/3 of their forearm on a piece of paper. We scanned it and imported the image into SketchUp.