2 Expert Tips to Give Your 3D Prints Smooth, Colorful Finishes

3D Printing & Imaging Craft & Design


The September edition of the Maker Educators Meetup at the Digital Harbor Foundation in Baltimore, Maryland, featured two remarkable 3D print finishing technique demos presented by co-hosts Shawn and Steph Grimes.

I have attended dozens of presentations on this topic, and having written previously for Make: on the subject of finishing — I found these two demos to be well worth the attention of Maker Educators looking to incorporate 3D printed parts into their curriculum!

If you find these techniques to be helpful, consider checking out their 3D Printing for Educators 4-day workshop coming up in October!


An Educator’s Guide to Affordable 3D Parts Painting Techniques

StephGrimes 3DPaintingDemo

Steph Grimes, DHF’s Director of Education, was the first to share. She presented the results of a series of experiments with affordable hobby paints on printed parts.

While many demos for painting/coating 3D printed parts emphasize sanding and priming as an essential first step, she rejected this route with a practical educator’s eye towards what the young Maker will be willing to incorporate into their own projects:

I wanted this process to be as quick and accessible for youth-serving audiences as possible so I skipped some “pro” steps. No sanding, filing, or priming was done before applying paint. While these actions may have improved the coverage of some paints, I chose to skip them for the sake of time.

She tested eight of the most popular solutions and ranked each on the following four criteria — Ease of Use, Coverage, Accessibility + Cost, and Kid-Friendliness — each on a scale from 1 to 5, where 1 is low.

She was thrilled to find that simple craft paints, well within the budget of most classrooms, came out the clear winner — check out her ratings for Sharpies, paint pens, gel medium, and more on the DHF website.

DHF CraftPaintResults

Painting Elaborate 2D Patterns Onto 3D Printed Parts In Seconds Using Hydrographics in the Classroom


Shawn Grimes, DHF’s Director of Technology, has been fascinated with hydrographics (also called “water transfer printing”) ever since he read about the technique applied to 3D printed parts by Le Fab Shop here on Make: last year. He wondered how useful this technique would be for the classroom, and was delighted to discover how easy it was to introduce hydrographic imaging to beginners.

This roughly thirty-year-old industrial manufacturing technique became available to auto and R/C-hobbyists a number of years ago — with hydrographic sheets for sale online and in hobby stores in a wide variety of patterns and images. Makers have recently started exploring these methods to quickly apply complex patterns to the surfaces of their projects. (And see recent coverage by Make: on research into printing your own hydrographic films using 2D image deformation processes to wrap realistic 3D skins onto dipped objects.)

Hydrographic sheets consist of two thin layers: a bonding film to preserve the pattern until use, and a 2D printed pattern suspended in a layer of water soluble PVA. (PVA is a popular substance used for water-soluble 3D printing filament.) To use the sheets, the designer gingerly places the film onto the surface of a basin of water, and then sprays an activating agent to break down the bonding film. The water-soluble PVA material then releases the image onto the surface of the water for dipping and coating the physical object.

Shawn spent time refining his technique leading up to the presentation, and shared in detail the steps he selected for presenting hydrographics in the classroom in the video below.

Here’s one of his most useful tricks. Attach a fragment of another printed part to the base of the part you are looking to coat to give yourself an easier handle for gripping and rotating the object as you dip it into the pattern. Guests at the demo suggested corn-on-the-cob skewers might work as well!

YouTube player

According to Shawn’s demo, and the response of the educators who attended the event, a key advantage to this process is how quickly a young Maker can transform a part produced using an inexpensive 3D printing material into something that looks like it is composed of something else — wood, glass, chrome, water, fire, or other materials — and this process bypasses the difficulties involved with designing these patterns into the surface of the 3D model itself.


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