@icorrea I don't think it has anything to do with the number of curves in your model. It's a fairly simple one. I agree with Rich. If you are having problems it's most likely the graphics card or its drivers. What version of SketchUp are you using? Share a screen shot of what you see. This is what I'm seeing. A few exposed back faces (blue) but no problem working in the model. [image: 1763125116883-glitching.gif]