I noticed it doesn't scrape well on rough surfaces. I am using it on glass with hairspray on it. I used these razor blades off Amazon, they fit well: https://www.amazon.com/Garvey-Economy-Single-Cutter-Blade/dp/B001GXFAEQ/ref=sr_1_1?s=hpc&ie=UTF8&qid=1499899884&sr=8-1&keywords=garvey+razor+blades
Printed in Hatchbox Silver PLA: https://www.amazon.com/HATCHBOX-3D-PLA-1KG1-75-SLV-Filament-Dimensional/dp/B00MEZEEJ2/ref=sr_1_1?s=industrial&ie=UTF8&qid=1501211390&sr=1-1&keywords=hatchbox+silver+pla
Printed in PLA. Took around 6hrs to print at 20mm/sec speed.