How to print your build

1Open a world

Open the editor and choose a source. "Sample world" loads a small world bundled with the app, which is the quickest way to see how everything behaves.

"Open world from folder" asks for one of your own saves. Pick the save folder itself — the one containing a "region" folder. Only the overworld is read; the Nether and the End are ignored.

Saves from Minecraft 1.13 and later use a different storage format and will not load yet. Pre-1.13 worlds work.

2Fly to your build

Click the viewport to take control, then move with W, A, S and D and look with the mouse. You start in the air, so you can get an overview before diving in.

Press Escape to release the mouse when you want to use the panels.

3Select a region

Switch on "Select region" in the top-left, then click two opposite corners of the area you want. The first click marks a corner in red, the second completes the box in green.

Once the box exists, drag the square handle on any face to move that face one block at a time. The panel on the left shows the exact minimum and maximum coordinates, which you can also type in directly.

Block editing stays available while a selection exists, so you can tidy up the build without losing the box. Only the panel’s Clear button removes it.

4Choose the detail level

"Normal" treats every block as a full cube — fast, robust, and right for large builds where a block is a millimetre or two.

"Micro" reproduces the real shape of each block: stairs step, slabs are half height, fences are thin. It is the right choice when the model is large enough for those shapes to survive printing, and it costs more triangles.

Micro detail also changes what counts as sealed, so hollow interiors are found more accurately — a stair roof no longer leaks.

5Check the preview

Press "Extract & preview" to build the model. Orbit it with the mouse in the right-hand panel.

The vertical slider cuts the model away from the top so you can look inside — useful for spotting cavities that will print as unsupported ceilings, or rooms you meant to keep.

"Remove interior" drops everything the outside cannot see. On a solid hillside that removes most of the volume, and with it most of the filament and print time. Sealed cavities stay sealed.

6Set the size

"Block size (mm)" decides the scale: it is how large one Minecraft block becomes. The printed dimensions underneath update as you type, so you can match your printer’s build volume before exporting.

Ten millimetres per block is a good starting point. Below about two millimetres, individual blocks stop being distinguishable and micro detail is wasted.

7Colours, if you have a multi-material printer

Switching on multimaterial groups blocks by colour and exports one STL per group, all in the same coordinate frame, zipped together with a manifest listing which colour is which.

Import the whole set as one object in your slicer and assign a filament to each part.

Each part is a separate watertight solid, so material boundaries become shared walls rather than gaps.

8Export

"Export STL" downloads a single binary STL; with colours enabled you get a zip instead. You need an account with a confirmed email address to download — that is the only thing an account is for.

The exported mesh uses unit faces rather than merged ones, which is what stops slicers from reporting thousands of "disconnected edges" and trying to repair the file.

9Slice it and print

Import the STL as usual. It should load with no warnings and need no repair; if your slicer offers to fix it, decline — the file is already watertight.

Blocky models print well with no supports as long as overhangs are modest. Print interiors hollow where you can: it is where most of the savings are.