Sticker Outline

Every "make a sticker from this image" workflow hits the same wall, and it isn't the cutout. BiRefNet or InSPyReNet will find your subject fine. What they hand back is a segmentation: a soft, wobbly, slightly ragged alpha edge with a grey fringe around it. Screen-print that, or send it to a vinyl cutter, and you get a dark halo plus a stair-stepped outline that looks like it was cut with pinking shears.

Sticker Outline is the deterministic cleanup pass that turns that into a cut line. No model, no sampler - pure pixel math, and that's the point. The pixels it hands back are the pixels you keep.

What it's doing, step by step

Alpha comes in (the image's own, or a wired MASK, which wins), and gets thresholded: at or above threshold is kept, everything else goes. smoothness is an edge-smoothing radius in source pixels - it rounds jaggies and small notches off the contour. min_speck_size deletes islands and fills pinholes smaller than that many pixels, which is how stray blobs from the segmenter disappear. keep_largest goes further and keeps only the biggest connected piece, and it runs first, so strays are gone before smoothing and closing can get confused by them.

close_gaps bridges gaps and bays open to the outside - the space between an arm and the body, a gap between two legs - so the cut line is one simple loop instead of a maze. fill_holes handles enclosed holes. Then upscale (1 to 8) does the trick that makes this node worth using for print: at 1× the alpha is binary at pixel scale, which is inherently stair-stepped. Work at 2–4× and the boundary is a smooth curve at final size. If your stickers look ragged when printed at 300dpi, this is the number, not smoothness.

The bit that solves the grey halo: edge. On blend (the default) the semi-transparent fringe ring is recoloured from the nearest solid pixel inside it, so the anti-aliased grey that a segmenter left around a white shirt stops printing as dirty grey. fill paints that ring with fill_color instead, for art that has its own drawn outline. keep leaves it as drawn. There's a band limit here worth knowing - only the outer ~3 source pixels count as fringe; deeper semi-transparency is treated as real texture and left alone, which is correct for a veil or smoke and occasionally annoying on a bad cutout.

border_width then adds a solid die-cut border in source pixels, with border_color as hex, and the canvas grows by that much on every side so the border is never clipped. antialias softens the finished edge to about a pixel for screen use - Discord, Telegram, a web gallery. Leave it off for print and cutting, which want a hard edge; the shape is identical either way.

Outputs are image (RGBA, alpha strictly 0 or 1 unless antialias is on) and mask (the final shape, in ComfyUI's convention where white = transparent, so it wires straight into Join Image with Alpha or any other mask node).

The settings order that works

Start from the default and fix one thing at a time: raise min_speck_size until strays are gone, then smoothness until the edge is clean but thin details (a finger, an antenna, a hair spike) survive - the tooltip's own rule is that details thinner than about twice the radius are lost. Add close_gaps if the outline has bays you don't want to cut around. Only then set upscale and border_width.

Installing it

Manager → search Nynxz → ComfyUI-NynxzNodes, or:

comfy node install comfyui-nynxz-nodes

From source:

cd ComfyUI/custom_nodes
git clone https://github.com/Nynxz/ComfyUI-NynxzNodes
cd ComfyUI-NynxzNodes
pnpm install && pnpm build

Restart after. No models to download - the whole point is that this node is math. It does import scipy.ndimage, and so do a couple of the region nodes in the same pack; ComfyUI normally brings scipy with it, but on a stripped-down container image a pip install scipy in the ComfyUI python env is the fix if the pack fails to import.

Troubleshooting

fill_color and border_color must be hex (#ffffff, #fff, hash optional). Junk in those fields raises a ValueError with the value quoted, so if your run dies with "must be a hex colour like #ffffff, got …", it's a typo, not a crash.

If the sticker comes out with a hard square edge somewhere, your source image is clipped at the frame boundary - this node never invents pixels outside the image, so a subject cut off by the canvas stays cut off.

And if close_gaps and fill_holes produced an ugly blob, check whether you have edge = blend and a fill_color you expected to be used: fill_color only affects close_gaps/fill_holes area and the fill edge mode. On blend the added area comes from the surrounding colours, which is usually what you want on art with no drawn border.

If the whole fringe looks like it was cut with a slightly wrong outline, that's the segmenter, not this node. Bit of a broken record in this ecosystem, but it applies: don't ask a segmentation model to do a matting job and then expect post-processing to recover the difference.