I am using sainsmart dark wood filament. It seems to be my best printing filament (though if I forget to set the temp for it it can get a bit stringy. I've had a bunch of trouble getting this thing up and running. BUT...now It does what I ask... and all the fiddling with everything has gotten me quite well acquainted with the ROBO The flash isn't flattering, but it looks perfect without the glaere to show off the fuzzies... didn't want to leave out the imperfections... If I turn down the temp the strings get A LOT better. I printed this one with the wrong preset... and by the time I noticed it.. 12 hours had passed. printed the whole thing in one go.