PETG HD Glass-filled [Formfutura 1.75mm] 750gHDglass is a high performance filament based on an unique PETG blend resulting in an amorphous, high strength, high gloss and ultra transparent 3D printer filament. HD stands for Heavy Duty, as HDglass is developed to have an optimal thermal stability and by that perfect 3D printing flowing behaviour, resulting in a very easy to print 3D printer filament with a remarkable high gloss, transparency and excellent properties with respect to strength,