We are very strict about the quality of goods that we let leave the factory and unfortunately sometimes product falls short of our standards. We have a very limited number of carbon fibre sheets, measuring 500mm x 600mm x 1.4mm which have surface finish defects, small scratches and pinholing... Structurally there is nothing wrong with this sheet - it is awesome in every way apart from surface finish. So if you have the time to do some sanding and a little lacquering, or the piece of carbon going into your project will not be on open view, save yourself a bargain!!! Half price!!!
This is still a seriously solid piece of carbon fibre sheet - and enough of it to last you for a good while - particularly if, like us, you keep a sheet of the size you need, then cut off a piece as you need it. 1.4 is moderately stiff and very springy.