Seam Settings: Hiding the Seam Line and Z-Seam Tips

If you have ever printed a cylindrical or curved part, you have almost certainly noticed that thin vertical line running along the surface. This "seam" is the point where the printer starts and finishes each layer, and while it cannot be eliminated entirely, the right seam settings can make it virtually impossible to spot. The good news: this is mostly a cosmetic issue that can be solved with just a few slicer adjustments.

Why does the Z-seam form?

FDM printers lay down each layer as a single continuous path. When the path closes, a small amount of excess material or a slight gap is left at the point where the nozzle stops and then moves again. When these points stack up on top of each other, they appear as a vertical line.

Seam position options

The main modes available in slicers for controlling seam placement are:

• Sharpest corner: hides the seam at a corner of the model; gives the cleanest result on boxes and angular parts
• Rearmost: keeps the seam consistently at the back, on the hidden face; ideal for vases and figurines
• Random: places the seam at a different spot on each layer; instead of a single line, it creates scattered texture – works well on organic surfaces
• Aligned: produces a single straight line; practical for parts that will be sanded afterwards

Other settings to reduce the seam

Once you have chosen the position, you can also reduce the seam itself. If retraction distance and speed are not set correctly, the nozzle will ooze or blob at the start of each layer. The coasting feature cuts pressure before the path ends, preventing excess material from accumulating at the final point. Keeping the print temperature near the lower limit of the material also reduces flow and makes the seam less noticeable.

Which method for which part?

There is no single correct setting; the geometry of the part determines the choice. For angular enclosures, the sharpest corner mode is usually best; for cylinders, random or rearmost typically gives the cleanest result. In our workshop, if a model has a clearly visible face, we deliberately direct the seam to the back – and sometimes repositioning the part on the build plate works better than any slicer setting.

The visibility of the seam also varies with colour and material: it shows less on matte filaments and more on glossy surfaces. Because material choice directly affects the outcome, you can check our production pricing page to see pricing and options.

If you have a part where the visible face is critical, send us the model and we will orient the seam to the most suitable position before printing.