Infill: how much material is inside the part

What infill is

In FDM printing a part is not solid inside. The printer makes solid walls, a bottom and a top, and fills the interior with a sparse lattice called infill. The percentage says what share of the inner volume is material, so at 15% the rest is air.

The lattice can have different shapes, from a simple grid to a wavy gyroid. You can find an overview of infill patterns in the OrcaSlicer documentation. You do not need to worry about the pattern, you only choose how strong the part should be.

Three strengths in our calculator

• Light, 10% infill. For mock-ups, decorations, figurines and parts that do not hold anything. It is the cheapest and lightest.
• Standard, 15% infill. A good choice for everyday things such as small boxes, covers, organisers or stands.
• Strong, 40% infill. For parts that carry something or get pressed on, such as wall brackets, handles or spare parts for the home.

If you are not sure which to choose, start with standard. Strong is worth choosing when a broken part would really bother you.

How infill changes the price

Higher infill means more grams of material and a longer print, which is why a strong part costs more. The difference is not directly proportional to the percentages, though. The walls, bottom and top are always printed the same, and only the interior changes, so with small and thin parts the price difference is small, and with large massive ones it is bigger.

You do not have to guess the exact figure. When you switch the strength in the calculator, we prepare the model for printing again and you immediately see the new price per piece and the weight.

Strength is not only about infill

How the part lies on the bed makes a big difference too. A printed piece is stronger along the layers than across them, much as wood is along the grain. The material counts as well: PETG is tougher and less brittle than PLA. If the part has to bear something, tell us what it is for and we will advise on orientation and material.