Differences Between Raft, Brim, and Skirt in 3D Printing

When you’re trying to get your 3D prints to stick to the printing surface better, you may come across some settings that allow you to actually print better adhesion. But what’s the best printed adhesion method for speed and reliability? Below we’ll compare three different adhesion methods to help you find the best settings for your projects.

	Raft	Brim	Skirt
Help Prime Nozzle Before Print	✅	✅	✅
Help Show Bed-Leveling Issues Before Print	✅	✅	✅
Connect to 3D Model and Increase Surface Area	✅	✅	❌
Most Reliable Adhesion	✅	❌	❌
Best Choice for Speed, Adhesion, and Least Waste		★

Brim

Printing with a brim is possibly the most widely used adhesion-assistant option in 3D printing. Brims are a single layer high and go around the perimeter of the objects to be printed. By printing connected to the objects, they increase the surface area exposure to the printing bed, making for a more solidly adhered print.

This is especially useful for prints that are small or objects that have little surface area touching the build plate. Because they are only a single layer high, brims typically print fairly quickly and waste very little material when compared to other printed adhesion options.

If you’re just starting out and your prints are having trouble sticking to the print bed, trying printing with a brim before moving on to other options.

Raft

Of the three type of adhesion settings that we’re covering here, rafts provide the best adhesion. But, they add both a lot of time and wasted material to prints. Unlike a brim, a raft covers all of the print surface below your 3D objects, meaning that your object won’t be in contact with the print surface at all. This greatly increases print adhesion for one simple reason: plastic adheres best to plastic. By putting down several layers of material and printing on top of that, the object you’re wanting to print is almost 100% certain to avoid adhesion issues all-together.

But while rafts can be helpful in specific circumstances and for not having any worries about adhesion, they are often overkill. For one, printing with a large enough brim will almost always increase the surface of prints enough to side-step adhesion issues. On top of that, waiting for a 3D print to finish already takes long enough to finish. Unlike a brim that is only a single layer, a raft is several layers high, and thus adds several minutes to a print.

Aside from taking up extra time and material though, using a raft has an additional downside: they can make the bottom of prints a bit rougher than if they were printed directly on the print bed.

Skirt

Although the “skirt” setting is often brought up in discussions of adhesion settings, skirts differ from other options in that they don’t actually connect to your printed objects. While rafts and brims increase the surface area of prints that touch the build surface, skirts do not.

So what are skirts good for? For one, they prime the nozzle to make sure that it your material is extruding properly before the printing of the actual 3D object begins. The second, and maybe more important thing that they do is help you make sure your printer bed is level before your print actually begins. If your print bed isn’t level, you’re inevitably going to run into adhesion issues as the nozzle either drags across the build plate or isn’t close enough for the material to properly adhere to the bed.

Because the other two types of adhesion assistant discussed above will also allow you’re nozzle to be primed and to see if you’re print bed is level, you should stick to using the skirt setting only when you’re sure that you won’t have any issues with adhesion.

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