Process › Quality› Line widthinitial_layer_infill_line_width

First layer infill line width

How wide the lines that fill the first layer are (sparse infill, solid infill and surface), without touching that layer's walls or supports. At 0 it uses the first layer width.

How it works

The first layer has two kinds of lines: the walls, which draw the outline, and the infill, which covers the inside and is pressed against the plate. This setting only controls the infill; walls, supports and everything else follow the first layer line width.

Bambu profiles set it to 0.5 mm, the same as the rest of the first layer: wide lines that squish well and close the bottom without gaps. If you set it to 0, it takes the value of “Initial layer”.

When to change it

A tray or a coaster whose bottom comes out with grooves or gaps between lines: raise it to 0.55 mm.
A name plate with a name engraved on the bottom that comes out blurry: lower it to 0.42 or 0.45 mm only here, and keep the first layer walls wide so it still grips.

Typical values

Value	What for
0	Uses the first layer line width
0.50	Default; closed, well-stuck bottomdefault
0.55	Bottoms with gaps between lines

Watch out for

Wider means more plastic on the slowest layer: if you overdo it, the nozzle drags plastic and leaves blobs on the bottom.
If the bottom doesn't stick, check the “Initial layer height” and how clean the plate is first.

Goes well with

Initial layer Initial layer height Bottom surface pattern

What Bambu Studio saysits help card, quoted

What Bambu Studio says

Line width of the infill of initial layer, including sparse infill, solid infill and top surface. Walls, support and everything else of the initial layer are not affected and keep using the line width of initial layer. Zero means to use the line width of initial layer.

Bambu Studio tooltip for this setting · AGPL-3.0