trial and error I guess...... I just knew there was better(a lot than the stock R/C skids stuff) plastic out there I could make skids from..... so I started looking around, I tried lexan first, and a few others but found the dangerous goods stuff to be THE best. I could take it a step further and actually use thicker dangerous goods grade stuff(from hydrocloric acid , spirits of salts etc etc containers), but its much thicker and heavier(but its super super impact resistant)

I guess I got some of the idears from my mates rally car....he uses kevlar and plastic skids on the bottom of a full size rally race car !!!!!... tougher than steel !

TM