Top surface flow ratio
Multiplies the amount of plastic only on the last layer, the top face. A little under 1 usually gives a smoother top.
How it works
On the top face you don't need to fill every last gap: if there's a little extra plastic, the nozzle drags it along and leaves ridges. With a factor of 0.95, that face gets 5% less material, the lines settle in without overflowing and the surface comes out flatter.
It only affects the top layer you can see, not the solid layers underneath it.
When to change it
- A box lid or a coaster with stripes or ridges between lines: lower it to 0.95 or 0.97.
- A top with grooves or gaps between lines: raise it to 1.02, or leave it at 1 and check “Top shell layers”.
Typical values
| Value | What for |
|---|---|
| 0.95 | Smoother top; some profiles use it |
| 1 | Defaultdefault |
| 1.03 | Top with gaps |
Watch out for
- A low value with only a few solid top layers can let the infill show through the top.
- In the program it's called “Top surface flow ratio”, and it only shows up with developer mode turned on in Preferences.
Goes well with
What Bambu Studio saysits help card, quoted
What Bambu Studio says
This factor affects the amount of material for top solid infill. You can decrease it slightly to have smooth surface finish
Bambu Studio tooltip for this setting · AGPL-3.0
Read more at the official source
In your profile0.20mm Standard @BBL A1 · 1
In Bambu Studio, the profile 0.20mm Standard @BBL A1 sets it to1
In other slicers
- Orca Slicer
- Top surface flow ratioQuality › Walls and surfaces
- PrusaSlicer
- No clear equivalent.
- Cura
- Top Surface Skin FlowMaterialAs a % (100% = 1.0). Only used if roofing_layer_count (top surface layers) is greater than 0.
Names taken from each program's code (Orca Slicer 2.4.2, PrusaSlicer 2.9.6, Cura 5.13.0). Credits