What Is Brim in 3D Printing and How It Works

In 3D printing, a brim is a flat outline of extra printed lines around the base of a model that helps improve bed adhesion. It acts like a collar attached to the first layer, preventing warping and lifting during printing.

How It Works

A brim works by adding several extra lines of filament around the base of your 3D print on the first layer. Imagine placing a wide coaster under a glass to keep it stable; the brim acts like that coaster, increasing the surface area touching the print bed.

This extra surface helps the print stick better to the bed, especially for small or thin parts that might otherwise lift or warp as the plastic cools. The brim is printed as part of the first layer but is not connected vertically to the model, so it can be easily removed after printing.

Example

This example shows how to enable a brim in a common 3D printing slicer using G-code comments for clarity.

gcode

; Start G-code
M140 S60 ; Set bed temperature to 60°C
M190 S60 ; Wait for bed temperature
M104 S200 ; Set nozzle temperature to 200°C
M109 S200 ; Wait for nozzle temperature
; Enable brim
; Brim width: 5mm
; This adds extra lines around the model base for better adhesion
; Print starts here
G28 ; Home all axes
G1 Z0.2 F3000 ; Move to first layer height
; Printing brim
; ... actual print commands follow ...

Output

No visible output; commands control the 3D printer to print a brim around the model base.

When to Use

Use a brim when your 3D print has a small footprint or thin edges that might not stick well to the print bed. It is especially helpful for materials prone to warping, like ABS or nylon.

For example, if you are printing a tall, thin object or a model with small contact points, adding a brim can prevent the corners from lifting and improve overall print success. After printing, the brim can be easily trimmed away.

Key Points

• A brim adds extra lines around the base to improve bed adhesion.
• It helps prevent warping and lifting during printing.
• The brim is printed only on the first layer and is easy to remove.
• Useful for small or thin models and materials prone to warping.

Key Takeaways

A brim improves 3D print bed adhesion by adding extra lines around the model base.

It helps prevent warping and lifting, especially for small or thin parts.

Brims are printed on the first layer and can be removed after printing.

Use a brim when printing materials or shapes prone to poor adhesion.