Layer height

Layer height is the vertical thickness of a single deposited layer in a print, determined by the nozzle opening, the extrusion rate and the travel speed of the print head. In construction-scale extrusion the values are typically in the region of 5 to 30 mm, depending on nozzle size; a common working assumption is that layer height sits somewhere between a third and a half of the nozzle diameter, so that the fresh layer is pressed slightly into the one below.

In practice

Layer height is a direct trade-off. A thinner layer gives a smoother wall face, better vertical resolution and more forgiving overhangs, but multiplies the number of passes and therefore the print time and the number of interfaces. A thicker layer builds height quickly but loads the layers below sooner and makes the ribbed surface more pronounced. Slight compression of each layer against the previous one improves interlayer contact; if the head sits too high the layers only touch, and the bond suffers. Because the wall gains height in fixed steps, layer height also determines how openings, sills and level changes have to be rounded in the model.

Related terms

• Nozzle — the outlet whose diameter sets the usable range of layer heights.
• Interlayer bond — the strength of the joint between successive layers.
• Layer lines — the visible horizontal ribbing left by each deposited layer.