A 3D print usually consists of a solid exterior, filled with a grid. This saves time and material, with the same model as a result. Of course you want the outside to be smooth and solid, but that can be a challenge for the top layer. How do you ensure a strong and solid cover on your product?

Prevent sagging

The solid top layer is printed on top of the mentioned grid filling the print. This means that the top layer has to span the holes in the infill. Logically, the material sometimes sags through those holes. To make sure that the material reaches the other side properly, you can do the following:

  1. Increase infill percentage

The infill is the foundation of your top layer. You can imagine it’s hard to create a proper top layer when the foundation exists mostly out of air. Try to increase the infill percentage to create a better bearing capacity for the top layer. Try to find the optimal ratio, so you don’t lose unnecessary material and time.

  1. More layers

Besides the infill, the number of printing layers can also be the reason as to why the top layer isn’t solid. The top layer exists out of multiple solid layers that are attached to each other. To ensure a smooth top layer, it has to be thick enough. As a rule of thumb, you can use a height of 0.75mm for the entire top layer. Depending on the printing height, you will therefore have to use several layers to reach a 0.75mm top. With the standard layer height of 0.25mm you would need  at least 3 layers for a solid top.