Know All About Raft vs Brim in 3D Printing

It is commonly believed in the 3D printing community that laying down the first layer correctly and smoothly breaks or makes a printed model. In most cases, getting that first layer done is 90 percent of the battle. Think of it as playing a role in the secret weapon against preventing 3D print warping.

We have all been there, keenly watching that initial layer go down correctly and the filament moves smoothly. That’s it, where the bed adhesion is where 3D print raft and brim come into play. One of the simplest ways to avoid poor bed adhesion is by using rafts and brims.

To put it into more simple words, rafts and brims are a common thing in the 3D printing world. Rafts and brims both are meant to prevent warping. Warping is the most common challenge faced by 3D printer users when printing at high temperatures.

They are based on similar basic principles, but both of them have their own advantages and disadvantages. Before understanding the difference between raft and brim in 3D printing, let’s understand what is the Raft? 

What is a Raft in 3D Printing?

A 3D printed raft is generally a spontaneous horizontal surface laid under the model. It’s formed of a prearranged number of layers, with a particular infill amount, that spreads a specific distance away from the model’s edges.

A raft begins with a few flat layers made up directly on the top of the printing bed of the model. The bottom-most layers are commonly printed slower and thicker than the top layers. This ensures that the base is rigid. 

You can also utilize rafts to provide advanced stability to the models with smaller footprints. The raft also offers rigid foundations significantly to the models that are heavy at the top.

The only drawbacks are that they add an extra filament and printing duration to the print, as well as potentially damaging the bottom layer of the model. With a raft, the bottom layer is destined to be rougher than printing on the plain glass anyway.

When to Use Rafts in Your 3D Printing?

There are numerous reasons for adding a raft. Here are the three standard steps that offer you complete ease.

  • Warping: Triggering a raft while using an ABS filament aids in preventing the print object from warping.
  • Greater Bed Adhesion: 3D printing rafts can assist in attaining better bed adhesion and simulating as a preventive measure against print failure.
  • Bed in Proportion to the Object: Suppose a print has small legs at the bottom, on which a heavy object is built. In such instances, it is advisable to add a raft to steady the printed model and avoid a print failure.

The utilization of rafts to reduce warping and augment bed adhesion has been a strongly established practice in the domain of 3D printing. It’s so handy that slicer programs generally come with options to add a raft to the existing model simply. 

Moreover, using it precisely gives you multiple benefits. One can save enough time and reach out to the desired results real soon. 

Just like a raft, a brim is a substratum used for 3D printing. Brims commonly consist of a mesh material. Based on their similarities, you may think they are the same. However, there are some differences between a Raft and a Brim in 3D printing. Let’s have a glance at the differences between both. 

Difference between a Raft and a Brim in 3D Printing

  • Built: 

The major difference between them is that rafts are built underneath the printed model. At the same time, brims are built around the printed model.

A brim can be best defined as a horizontal and flat expansion of the printed model’s base layer. While rafts are positioned underneath the printed model, brims are placed around the printed model, basically creating the appearance of a skirt.

  • Construction:

Another difference between brims and rafts lies in their construction. However, there are exceptions; rafts contain many layers, whereas brims have a single layer.

  • Adhesion:

Both brims and rafts can be utilized in 3D printing. Of these two choices, the former is naturally the better choice. Rafts form better adhesion than brims because they are positioned underneath the printed model. It helps the items to stick together, therefore improving adhesion.

Obviously, the limitation of using rafts is that they are comparatively tougher to separate from the printed model than brims. Since they support better adhesion, the model sticks to the raft. Therefore, more force must be applied to separate a raft from the printed model.

  • Contact with the print model

Both rafts and brims can prove very useful in stabilizing models with the slightest contact with the print. Although, you may choose a brim over a raft as its contact with the print model is on the outer sides.

  • Waste Material

Like other support objects, a raft also wastes material that does belong to the workpiece. However, a brim assists in keeping the waste within acceptable limits. 


Is there a difference between a raft and a brim? The difference between the two is how they both work. The raft refuges underneath the print model while the brim touches the long sides only. 

With that said, many corporations still choose to utilize rafts over brims due to their strong adhesion properties. Both components act as a substratum on which the respective model is built. 

Don’t forget that rafts and brims of 3D printers aren’t the only remedies to fight to warp. You can try printing at a decreased temperature, using a printing bed enclosure, or priming your build platform with an adhesive substance. When it arrives at 3D printing, there’s always more than one solution to a problem.

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