First of all, make sure you got a good print: well-leveled build plate, clean extruder, no warping, etc. If the print looks like it printed well and you’re still having issues, please contact us. We’ll be happy to help. Here are a few things to look out for – each brand and color of filament weighs and behaves a little differently. Try the same print in a different color or brand. If you’re working with one of the density-sensitive kits, the infill amounts may need to be tweaked to suit your particular brand of filament. For best results when working with density-sensitive kits, print the whole kit in the same color unless otherwise instructed and verify the model before using in a teaching environment.