Extrusion width

As your printer lays down lines of malleable plastic to bring your model to life, the hole in the nozzle impacts how wide those lines are. You can also think of it as your thread width, how wide the thread of plastic that comes out of your nozzle is. A more technical term is extrusion width, how wide the extruded plastic is. That width isn't necessarily equal to your nozzle size. For example, a nozzle with a 0.4mm hole may be using a 0.42mm extrusion width.

Find Your Extrusion Width

You may be able to look up your extrusion width in your slicing software. Different slicers use different terminology. Three examples are:

If you aren't able to look up your specific extrusion width, start by designing for your printer's nozzle size instead.

Extrusion width is important to consider during design as it can also impact the detailing of your piece, which is most readily visible on the top. Later in the book, we will create a bracelet with custom coordinates on the top. If that piece was printed flat on the bed and portions of text were thinner than the extrusion width (such as part of the number 4 in the following image), that detail could very well get skipped:

A section of the number four in the coordinates is thinner than the extrusion width, so it is skipped by the slicer and printer.

Layer heights are smaller, sometimes substantially so, than extrusion widths. That means detailing going up vertically can be finer than the horizontal details you have at the top. If we printed that coordinate bracelet on its side, the same number we had trouble with before shows up fine:

Vertical details can be finer than horizontal ones.