It’s been some time since I wrote an update about our Slic3r Prusa Edition development. 352 commits on the GitHub project to be more specific since the release of the Smooth Variable Layer Height feature. Since then we were mainly focusing on solving bugs and adding features for our Multi Material upgrade.

But first, let’s do a little recap of the more notable additions.

  • Version 1.33.3 introduced Smooth Variable Layer Height.
  • 1.34.0 came with parallel processing and up to 4 times faster slicing, smoother g-code preview and a better memory usage.
  • 1.35.1 was the first version to make multi material printing easier thanks to the integrated Smart Wipe Tower. Users previously had to use external post processor to generate the tower. Different extruders can also have a color assigned making the g-code preview accurate.
  • 1.35.3 brought a better 3D scene manipulation.
  • 1.35.4 enabled loading settings from sliced g-code files and added “Split part” button in the object setting. It enables you to print parts of the multi object stl with different materials.

Remember there are many version in between fixing hundreds of bugs and adding tiny improvements, you can always dive into the detailed release logs at our GitHub

So now we got to the latest version 1.36.2 which improves printing with water soluble supports.

Printing with supports on Prusa i3 MK2 MultiMaterial

You have three ways to print with support. Basic supports from the same material as on regular MK2/MK2S, water soluble supports everywhere and water soluble only on the interface layers. You can see all three methods below on the prints of Pegasus.

Pegasus by dot-kit

Basic supports from the same material

Same supports as on the regular MK2S, keeps the ability to print 4 materials/colors and it is very cheap as a regular material is used. The finish of supported surfaces isn’t always as pretty.

With water soluble material everywhere

PLA supports vs. Soluble supports

Water soluble materials (BVOH in this case) produce much better surface finish on the supported side, comparable for example to the top side of the model. Some objects require a lot of supports rendering this method very expensive. Water soluble material needs to be placed in the extruder 4 and use NORMAL SOLUBLE FULL print settings.

PLA vs. Soluble supports detail

Driftwood print in 2 materials + support

Gyro the Dodo

 With water soluble material only on the interface

Big Whale Jumping in 2 materials + water soluble interface support

Using a water soluble material only for support interface layers brings the best of both worlds where majority of the support structure is printed with a regular cheap print material and you still get the amazing surface quality as with the full soluble supports. This cannot be used on objects with supported inaccessible internal geometries as insoluble parts of support would remain trapped. Again water soluble material needs to be placed in the extruder 4 and use NORMAL SOLUBLE INTERFACE print settings.

Big Whale Jumping in 2 materials + water soluble interface support

Taximeter panel

Taximeter panel detail after support removal


During our testing we stumbled upon two materials which work incredibly well with Multi Material. First is BVOH from Verbatim and second is PVA from Primaselect. We carry both on our e-shop. Other soluble support materials we tried were very stringy and occasionally jammed the multiplexer.

BVOH compared to regular PVA produces much less stringing and can be basically printed with PLA print settings. It is very easy to use and doesn’t absorb air humidity as much as PVA. A nice little bonus is that most of the time it can be easily and cleanly broken off the model so you do not have to messily dissolve it in water, or break away the most and dissolve just the stubborn stuck pieces. Primaselect PVA proved to be almost as good as BVOH but absorbs the air humidity faster and introduces a tiny amount of stringing.

Always store the water soluble materials in a sealed bag with some desiccant.

Download the latest 1.8.0 drivers with Slic3r PE 1.36.2!

Get Multi Material upgrade from our eshop

Happy printing.

Used models: