Brim vs Raft in 3D Printing: Key Differences?

Struggling with 3D prints that lift off the bed or warp at the corners? You're not alone—poor bed adhesion is a top frustration for new 3D printers. Brims and rafts are simple slicer settings that solve this by adding extra filament layers for stability.

In this guide, you'll learn what brims and rafts are, how they differ, when to use each, and pro tips for success. No advanced knowledge needed—just your slicer software like Cura or PrusaSlicer. Expect to grasp the concepts in 15 minutes and apply them to your next print.

By the end, you'll choose the right support every time, saving filament and failed prints.

▸What You'll Need

• •Access to 3D slicer software (e.g., Ultimaker Cura, PrusaSlicer—free downloads)
• •Basic 3D printing knowledge (e.g., what a slicer does)
• •A 3D printer (any FDM model like Ender 3)
• •Optional: Clean print bed and adhesion aids like glue stick

Estimated Time: 15-20 minutes to read and understand Difficulty: beginner

▸Step-by-Step Instructions

Step 1: Grasp Bed Adhesion Basics

Bed adhesion is the foundation of successful 3D prints. Without it, prints warp, lift, or fail completely due to uneven cooling and shrinkage.

Why it matters: Materials like PLA contract as they cool, pulling edges up. Brims and rafts anchor the print.

Expect: A stable first layer prevents 90% of adhesion fails.

💡 Tips:

• •Clean your bed with isopropyl alcohol before each print.

Step 2: What is a Brim?

A brim is a thin, single-layer (or 2-layer) skirt of filament around your print's base, typically 5-15mm wide.

How it works: It expands the footprint for better heat distribution and grips the bed, countering corner lift.

Analogy: Like training wheels—minimal but effective for most prints. Uses little material (1-2g).

💡 Tips:

• •Start with 8-10mm width for PLA.

Step 3: Setting Up a Brim in Your Slicer

In Cura: Go to Prepare > Build Plate Adhesion > Brim, set Line Count to 8-10, Width to 5mm.

Why: Quick setup improves success rate without much waste.

Slice and preview—the brim appears as an outer ring.

⚠️ Warnings:

• •Don't overuse; too wide wastes filament.

Step 4: What is a Raft?

A raft is a thicker platform (2-3 layers, 1-3mm high) fully under your print, with a larger brim-like edge.

How it works: Provides a uniform base that absorbs warping and ensures level first layers. Great for ABS or tall prints.

Analogy: Like building on a solid foundation—stable but material-heavy (10-20g+).

💡 Tips:

• •Use air gap of 0.2mm for easy removal.

Step 5: Setting Up a Raft in Your Slicer

In Cura: Build Plate Adhesion > Raft, set Initial Layer Line Width to 150%, Layers to 3.

Why: Ideal for tricky materials/orientations.

Preview shows a full base layer.

Step 6: Brim vs Raft: Core Differences

Key takeaway: Brim for efficiency, raft for stability.

Step 7: When to Use Brim vs Raft

Use Brim: Small/medium prints, PLA/PETG, good bed adhesion already.

Use Raft: ABS/ASA, large prints, uneven beds, first-time exotic materials.

Test both on scraps to see what sticks best.

💡 Tips:

• •Disable both if bed is perfect.

Step 8: Pros, Cons, and Removal

Brim Pros: Saves filament/time, easy peel. Cons: Less warp control.

Raft Pros: Superior stability, level base. Cons: Wasteful, stringing risk.

Removal: Heat bed to 50°C, flex plate, use spatula gently.

⚠️ Warnings:

• •Never force removal—risks damaging print.

▸Pro Tips

• •Calibrate bed level first—flawed leveling amplifies issues.
• •Use enclosure for ABS rafts to reduce warping.
• •Set brim/raft speed to 30mm/s for best adhesion.
• •Combine with glue stick for 99% success.
• •Preview G-code layers to verify setup.
• •Start brim width at 10mm, adjust per material.
• •Rafts shine on bowden extruders—less ooze.

▸Common Mistakes to Avoid

• •Using raft for every print—wastes filament unnecessarily.
• •Zero brim width—ignores slight adhesion tweaks needed.
• •Poor removal technique—snaps print edges.
• •Ignoring material type—PLA doesn't need rafts.
• •Not cleaning brim/raft residue—ruins next print.

▸Troubleshooting

Problem: Brim/raft not sticking to bed

Solution: Clean bed, add glue stick, increase bed temp by 5°C.

Problem: Print detaches from brim/raft

Solution: Increase interface layers or air gap to 0.1mm.

Problem: Stringy rafts

Solution: Enable retraction, lower raft temp by 5°C.

Problem: Hard removal

Solution: Heat bed post-print, use fishing line to cut.

SUNLU 3D Printer Glue Stick (2 Pack)

Boosts adhesion for brims on glass/PEI beds, preventing lifts without rafts.

Best for: Daily PLA prints or when brim alone isn't enough.

Price Range: $9.99

Wham Bam PEX Build Surface

Magnetic, flexible sheet pairs perfectly with brims/rafts for easy removal.

Best for: Ender 3/CR-10 users needing warp-free bases.

Price Range: $29.99-$39.99

ScotchBlue Painter's Tape (1.88in x 60yd)

Cheap bed cover enhances brim grip for textured adhesion.

Best for: Budget beds or PETG/ABS rafts.

Price Range: $5.99

eSUN ABS Filament (1.75mm, 1kg)

Wants raft most; test adhesion aids effectively.

Best for: High-warp materials needing rafts.

Price Range: $19.99