B-Stock filament contains minor cosmetic defects only. Guaranteed to have the same material quality, diameter, color, and weight as our regular inventory. B-Stock filament is also guaranteed to be tangle-free. Nylon-12 Filament is the ultimate solution if you need tough parts with great heat resistance! It exceeds ABS in strength, toughness, and temperature resistance (hot and cold). It is less hygroscopic* than Nylon-6 (absorbs less moisture) and has improved printability making it easier to work with. Filament Specs: Hotend Temperature (°C): 230-270 (Recommended: 255) Bed Temperature (°C): 0-125 (Recommended: 60/90) Filament Diameter (mm): 1.75±0.05 Net Weight: 1kg (2.2 lbs) Build Surface: Garolite, or PEI w/ Glue Stick Print Parameters: We have spent thousands of hours testing our filament with several printer types and recommend these printing settings. Default Print Speed: 30-60 mm/s (Recommended: 35 mm/s) First Layer Height: 0.24 mm First Layer Speed: 15 mm/s Extrusion Width: 0.48 for 0.4 Nozzle (1.2X Nozzle Diameter) Retraction: Bowden 5mm @ 45 mm/s or Direct 2mm @ 45 mm/s Perimeter Print Speed: 70% of Default Print Speed Infill and Support Print Speed: 80% of Default Print Speed Fan Profile: Layer 1: 0% Layer 3: 0% Layer 4: 0% Layer 5+: 0% XY Jerk: 8 Z Jerk: 0.3 E Jerk: 5 Acceleration (Print/Travel): 300/500 Retract Acceleration: 1000 Travel Speed (non-print moves): 120 mm/s Special Notes: Nylon is extremely hygroscopic (absorbs water from the air). You must dry before use and store in a sealed container with desiccant packets or similar.