Best filler for PLA?

I am only guessing, but since Automotive Spot Putty works on plastic body filler I don't see why it wouldn't work in your application.

John

I spoke with my son who has a couple 3D printers and used them a lot for robotics.  He hasn't had a need to do this, but he said a lot of people will use a 'filler and sandable' primer (often used for automotive painting).

Then you lightly sand it with a fine sandpaper.  Depending upon your application, it may take a couple rounds of sanding and coats.

I don't have experience doing this, but I have to wonder if you have a smaller item you are working on whether it would be easier to apply than a putty.  It seems like it might be easier to keep the original shape of the object.

To be clear, I'm not saying a putty would not work; I think it depends upon your situation.

If you use either the filler/primer or the putty, it would be great to know how it worked.  Maybe even before and after pictures.