2.2lb (1kg) rolls of polycarbonate. Polycarbonate is a thermoplastic, it's strong and impact resistant (It's used in the making of bulletproof glass and compact discs) temperature resistant and it can be extruded (at the right temperature). It can be bent and formed while cold without cracking or deform and it is also very optically 'crystal' clear to visible light (opaque to UV light), but it's actually not very easy to keep it clear during extrusion, see below -
Don't confuse Polycarbonate with Acrylic or Plexiglass, they shatter and crack, Polycarbonate tends to just bend and deform and after much effort will eventually stretch like very hard rubber until it eventually breaks.
Marketed under the trade name Lexan, it is used to make products as varied as CDs and DVDs, bullet proof glass, riot gear, sunglass lenses, scuba masks, electronic display screens, phone and computer cases and much more.
Polycarbonate has a glass transition temperature of about 150 °C (302 °F), so it softens gradually above this point and flows above about 300 °C