Used my bodyweight to bounce on two 18" Sempertex Crystal Stuffers. Bounced for a few minutes and felt the soft latex stretch and give with my weight. The crystal's are yellowy until they are full of air. They have a bit of a gloss but are clear and feel special. They look delicate but can withstand my weight so I consider them to be perfect for bouncing. After I got my bouncing in, I grabbed a pen and finished them off quickly. I liked having that hard ending to my bounce ride. Game over.