Paint Bottle Cap Swatch Adapter

This design consists of two simple models which can be combined directly in your slicer with the model of your choice to create a custom paint bottle swatch cap for typical 17/18ml paint bottles (such as ArmyPainter and Vallejo).  These can then be painted to show off the actual resulting paint color on a typical mini (this is in particular useful with Speedpaint).

Instructions

• Load a model of your choice in your slicer (I use PrusaSlicer, but the following should work in all modern slicers)
• Add both of the models (bottlecap-full.stl and bottlecap-cutout.stl) as parts to it (in PrusaSlicer, you do this by right-clicking your model and selecting “add part”). Make sure to add both at the same time, so they are centered with each other.
• Make the bottlecap-cutout.stl part a “negative volume”  (in PrusaSlicer, right-click on the part in the parts list, then select “Change type”, and then “negative volume”).
• Select only your model and reposition and resize it to your liking (make sure not to resize the bottlecap models!)

Note that the combined model might not look like it has the cutout - but the cutout should correctly appear after slicing.

Examples

To give you an idea of how it works, I have provided a 3mf file where I did this for a couple of examples, from these great models (all with CC licenses):

• https://www.printables.com/model/608702-vogland-orc-miniatures-head-set-two
• https://www.printables.com/model/152255-34-mimic-chest-no-supports-needed
• https://www.printables.com/model/1192240-beholder-miniature
• https://www.printables.com/model/991594-mega-sized-lego-like-star-wars-stormtrooper-captai
• https://www.printables.com/model/342693-darth-vader
• https://www.printables.com/model/1079210-mandalorian-helmet

Model recommendations

I strongly recommend using a relatively simple model which does not require supports (since you'll be printing many of these). At the same time, make sure it has sufficient recesses to properly show off the shading (especially for Speedpaint). And don't forget that you can rotate your model to change its orientation on the bottlecap.

Printing

I print these in PLA+ with a 0.25mm nozzle at 0.1mm layer height, but depending on the model (and your printer), a 0.4mm nozzle and 0.2mm layer height should give decent results as well.

Assembly

Depending on your printer tolerances, you might be able to just pressure-fit the swatch onto the bottle cap. But I still recommend adding a drop of glue to fix it in place.

Enjoy and post your creations as remixes!