>>> Hi. We're a group of students from Sherbrooke University in Canada and > we're working on a long term project. It consists of designing and > building a surfboard. We're wondering there is a criterion to evaluate the > roughness of the surface of our board. Is there a way to mesure that kind > of caracteristic? Thanks for your help... That would depend on what surface you are talking about, ie... foam,laminating coat, sanding coat or perhaps a glossed finish. In any event you can determine the surface roughness through the grades of sand paper you are using. When sanding with 180 grit you sand until you can no longer see the scratches left by the 80 grit or whatever previous grit you used, keeping in mind not to remove too much of your glass coat. When polishing, you use the same theory applied to the polish until tou achieve a glass like surface. Good luck. M.