Finish Up Your ABS 3D Printed Model With Pen Torch

https://www.youtube.com/watch?v=0T2pX9SHomI

Problem statement:

Most of the time after you remove the support printing materials there will be some white marks in some places.

Solution:

You can use flame / fire to restore back the ABS color to its original. You can use a lighter but I prefer to use a torch because it is much faster and usually do not leave any black mark on my models.

See my video here