Horizontal Brick Layers – PrusaSlicer Modifier

Horizontal brick layers modifier

Updates:

2026.09.25:

• I added "This Way Up" icons to the top of all of the modifier STLs because it can get very confusing very fast if you rotate a model. It is important that the modifier be correctly oriented, and direction does matter.

• I also learned that if you add the modifiers to your Shape Gallery, it REALLY simplifies implementing them! When loading modifier from the shape gallery, rotation and dropping the modifier to the bed are no longer required. All you have to do is add the modifier from the gallery and move it over the part and then add the perimeter settings to the modifier, even if you've rotate the part!

Method:

1. Import model to build plate

2. Right-click on imported model

   1. Select "Add modifier" → "Load ..."

   2. Select the brick layer modifier file from your downloads. Be sure to use a modifier that completely covers the object you are printing.

   3. Under "Part manipulation," click the "Drop to bed" icon

3. Right-click the modifier (in the 3D view or the object list)

   1. Select "Add settings" → "Layers and Perimeters"

      1. Tick "Perimeters"

      2. Click "OK"

4. Right-click the modifier (in the 3D view or the object list)

   1. Select "Add settings" → "Extrusion Width"

      1. Tick "External perimeters" and "Perimeters"

      2. Click "OK"

5. In the right panel, you will now see the modifier settings options. At the bottom:

   1. Under "Extrusion Width," set:

      1. "External perimeters" to 0.675 mm

      2. "Perimeters" to 0.675 mm

   2. Under "Layers and Perimeters," set:

      1. "Perimeters" to 2

6. Slice.

7. In the Preview, scrub through the layers to verify that the perimeters alternate between three narrow (0.45 mm) perimeters and two wide (0.675 mm) perimeters. Setting the view type to "Width (mm)" will make this very easy.

Load the object:

Load the modifier:

Switch to front or side view (3, 4, 5 or 6 on keyboard):

With the modifier selected, click the "Drop to bed" icon under "Part manipulation":

right-click on the modifier:

right-click on the modifier:

Change the values for perimeters and widths:

AND... SLICE!

Theory:

All of the 3D printing "brick layers" modifications I have seen focus on staggering alternating perimeters in the Z axis. This seems inefficient since it only marginally increases contact between layers, and is not how bricks work. The following method increases layer contact by changing layer width on alternating layers as a way to increase interlayer contact between perimeters.

I do not have the equipment to strength-test this method, so I'm offering it to the community to test. If you test it, please post your results.

Assumptions:

• The following procedure is based on PrusaSlicer 2.9.6. Modifying the procedure for OrcaSlicer and Bambu Studio should be trivial.

• 0.4 mm nozzle

• 0.2 mm layer height

• 0.2 mm first layer

• 3 perimeters

• 0.45 mm extrusion width for perimeters and external perimeters

• No variable layer height

• Brick layer files have been downloaded

Recommendations:

• Turn off perspective view in the slicer - this will reduce rendering load on the graphics and make the model viewable in the slicer when viewed from the sides.

  • Pressing 'K' switches between perspective and orthographic views.

Caveats:

• Since PLA prints typically fracture flat across a single layer, this will either have minimal improvement on part strength or no improvement at all. For filaments like PETG, PCTG, and nylons that tend to have better interlayer adhesion where tests often show fractures across multiple layers or even tearing across multiple layers, this procedure may improve overall strength.

• The procedure is for a single object. If you want the modifier to cover multiple objects you will need to either apply the modifications to each object, or merge them into a single object.

• When working with multiple copies of the same object, applying this to one object will be automatically replicated across all of the other copies.

• The modifier is loaded such that the bottom of the modifier is set above the build plate. See 2. 3.

• There will very likely be an impact on the surface look or quality with the alternating external perimeter widths.

• If you rotate the object after importing in X or Y, the modifier will be rotated to match that rotation. This procedure assumes the object sits as loaded. If you rotate the object, you will need to counter-rotate the modifier accordingly.

• If you want to use these modifiers for layer heights other than 0.2 mm, you will need to scale the modifier accordingly. That is an exercise for others.

• If your perimeter width is different than 0.45 mm, you'll need to make the appropriate adjustments.

• If you want to use more than 3 perimeters, you will need to make the appropriate modifications to the instructions.