# What's smoother? Acetone treated PLA or ABS

From my understanding, both PLA and ABS can be treated with acetone to make them smoother. So when they are treated with acetone, which is smother PLA or ABS or are they about the same?

When I search online, all I find is how to treat the objects.

• PLA is not soluble in Acetone. – tjb1 Jun 14 '17 at 17:45
• @tjb1 That is not quite true. I have noticed that a PLA part (which I used as a stand when smoothing ABS parts) did get noticeably smoother after a few uses. I'm not sure if that's due to the PLA being impure, but I'm not convinced PLA is entirely insoluble in acetone. – Tom van der Zanden Jun 14 '17 at 18:49
• @TomvanderZanden soluble would indicate that the material dissolves in the liquid. I've never seen any of the PLA I have dissolve in Acetone and I've not found anything online that shows it dissolving or changing the color of the Acetone. I have found references to PLA swelling in Acetone but not dissolving. – tjb1 Jun 14 '17 at 19:15
• Just to clarify, you say When I search online, all I find is how to treat the objects. - by objects, do you mean the finished printed items? Do you want to smooth the printed items, or something else (i.e the filament itself)? Or are you saying that the articles that you found only describe how to treat the prints, but they do not compare the smoothness of treated PLA and ABS? I guess you mean the latter. This article Acetone Finishing on PLA has some good points raised in the comments about whether PLA can be treated – Greenonline Jun 16 '17 at 19:15
• @TomvanderZanden Most PLA filament has additives, sometimes including ABS, sometimes just dye. Often, those additives dissolve in acetone. I have never been happier with the result after trying to smooth PLA with acetone than I was before I started. Usually, it just seems to permanently soften and become porous, which is not a good look. – fectin Jun 17 '17 at 1:17