If you’re thinking of buying this fabric Hiroshi, then the general consensus here is to not buy it. Extremtextil have some very heavy tpu coated nylon which they describe as ‘high tenacity’, but all the others are not, and the fabric melts at almost the same temperature as you need for welding. Andreas says he will buy Matt’s fabric next time, not the one you are looking at.
I had to abandon a sleeping mat project, after buying enough fabric to make two mats and cutting it all up ready, because it just melted.
Everyone who has tried this ‘low tenacity’ fabric says to not do it again. For my first boat I bought a kit off Matt, and for the second boat I will buy green fabric off Matt – we know that this fabric is good.
Please do not buy any fabric that is not ‘nylon 66’.