[Source] Refractory coating was applied to the personal ray shields used in the final round of the Big Game on the Wheel. The substance was not powerful enough to withstand normal blaster bolts, but it could reflect the weaker blasts of the needle rays used in the Big Game. A blast so reflected lost little of its potency, and was still deadly. By hiding a ray shield with refractory coating under his shirt, Han Solo was able to fake his own death from a needle ray blast.