Painting PLA 3D Printed Plastic.

The valve body part I use for everything from machine
calibration to well, paint tests! 

One of my newer endeavors is running the 3D printer at work.  And with any new journey, it's got is rewarding victories, and frustrating setbacks. 

My most recent "let me figure that out" moment came when printing a "presentation" part, meant to give an idea of shape and volume.

I printed the company logo into the part, because that's just good marketing right there.  But then came the suggestion....

"Can we paint the logo to make it pop?  Do we have an white out anywhere?" 

After a build lasting 22 hours, I wasn't willing to roll the dice with white out.  But while home sick, recovering from the flu, I had an idea (fever dream?) to go to the local crafts store and see what they had for paint. 

So once recovered, I wandered off to the crafts store and found a paint pen.  Not willing to try my first attempt on the part at work, I tried it on another PLA part I had. 

The results for a first attempt weren't too bad.  We're they perfect?  No. but it'll do for what we're currently after, and if I do say so myself, not bad for a first attempt.

The "paint pen" and its willing test piece

Have you got any suggestions for painting PLA?  I've heard acrylic and spray paint work well, but haven't tried it myself.  For that matter, has anyone tried the good old fashioned whiteout?  Maybe I'm being a little elitist and it really is a good choice!