Table of Contents
Introduction
If you haven’t yet, check out my article on the Velocity Painting technique. To quickly summarize my previous work, this post processing technique varies the speeds of your model’s outer shell to give it a texture, picture or design.
This is a very cool concept and I applied it to a few different vases and to the ever faithful Skully. While printing the Skully I noticed some EXCESSIVE ‘stringing’ in the infill of the model. I thought nothing of it and sliced up a file for a 3D printed hand with a checkerboard pattern ‘painted’ on it. This is when it became glaringly apparent that something was wrong. Which led me to investigate what could be causing this Velocity Painting issue.

What’s the Velocity Paint Issue?
I had to stop the print. Something was wrong, REALLY wrong. I haven’t had a print that looked this bad in a very, VERY long time. The amount of stringing was so bad that I thought there was something wrong with the filament. I loaded up the original file of the UnLimbited Phoenix hand and it started to print without issue on the same printer with the same Hobby King Transparent Red filament. Hmmm!?

While watching the modified file print, I had noticed what looked like stringing from excessive heat. Except the problem wasn’t due to heat. The extruder was extruding on some of the travel moves! After opening the modified Gcode file, my suspicions were confirmed. The Velocity Paint issue was in the modified Gcode. I opened up the original Gcode and could see that problem wasn’t there.
Verifying Settings and Reslicing
I went back through my settings and verified that I hadn’t accidentally changed anything. My infill, top/bottom, and walls were all set to the same speed. I even changed my initial layer to being the same speed as the rest of the model. The Velocity Paint issue remained.
I changed the speed of the travel moves to much higher, and I changed retraction speeds. The biggest change came from disabling retraction completely. This cleaned up the model a little bit, as I show below, but STILL the Velocity Painting issue remained!

How About a Different Slicer?
Maybe it’s something that Cura is doing? I decided to try out KiSSlicer. This is a pretty rough profile, but I just wanted to see if the problem was related to some kind of wipe/retraction that Cura was doing. I sliced up my rough draft on Kisslicer and ran it through Velocity Paint. The problem was GONE in the layer view. I even went back and used an older version of Cura and the problem was still there. So the problem seems to be related to however Cura handles travels.

So What Now?
I have reached out to the team at Cura and also to the Velocity Paint app’s creator, Guillaume.  I will update the article with any further information that I receive, but for now, I would hesitate to use any kind of Velocity Painting technique with any version of Cura (as of v3.6).
André
Hi Andrew,
In January I encountered this problem as well. I have now updated and revisited the software and the issue persists, still. I have also tried to figure out what it could be in the Gcode that sets the cura files apart from other slicers. Do you have any information on that? And has there been any feedback from the velocity painting or cura creators?
Best wishes
admin
I have not seen any update on this sorry we couldn’t help