Polka Dot Pattern (Purz)

Sometimes you just need a clean polka-dot texture and you don't want to alt-tab to a design tool, export a PNG, and drag it into input/. PurzPolkaDotPattern generates one as a real IMAGE output right in the graph - set colors and spacing, hit run, and you've got a texture you can composite over a render, use as an img2img source, or pipe into a mask operation.

It's part of purzbeats' ComfyUI-Purz pack, and it's about as no-frills as nodes get: no models, no weights, no downloads. You feed it numbers, you get pixels.

How it works

Under the hood it's plain Pillow drawing. The node lays down a grid of circles with ImageDraw.ellipse, starting each row offset by half the spacing when stagger is on - that's the classic "brick" polka-dot layout you see on wrapping paper and retro tees, where dots in alternate rows sit between the dots above them. With stagger off you get the straight rows-and-columns version.

The inputs that matter

• width / height - output size, 64–4096 (step 8, so keep them multiples of 8 if you're feeding a latent later).
• dot_radius - 2–100, default 10. Bigger than that and dots start overlapping into blobs.
• spacing - 10–200, default 40, the gap between dot centers. This is the real "density" dial.
• background_color / dot_color - hex strings like #FFFFFF and #000000. Two-color only; no gradients here.
• stagger - boolean, default on. Off gives you the aligned grid.
• batch_size - 1–16. Bump it if you're generating a stack of identical textures for a video or batch workflow.

Output is a single image (IMAGE), one tensor per frame in the batch.

Install

It ships in the same pack as the rest of the Purz nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/purzbeats/ComfyUI-Purz.git
cd ComfyUI-Purz
pip install -r requirements.txt

then restart ComfyUI. Or just search "ComfyUI-Purz" in ComfyUI Manager. No model files, no API keys - the heaviest dependency is OpenCV, which you almost certainly already have.

Where people get burned

• Hex format matters. It parses #RRGGBB; drop the # or use a short form and you'll get colors the node doesn't understand. Keep the #.
• Radius vs. spacing. If dot_radius is more than about half of spacing, the dots mush together - sometimes that's the look you want, but it catches people off guard when they expected dots and got a dotted field.
• Batch frames are identical. With batch_size > 1 every frame is the same pattern; there's no seed to vary them. For actual animation you want the pack's animated polka dot node, which is a separate class.

Honestly, that's the whole node. If you need a dot texture as part of a workflow, it saves you the round-trip; if you need dots that move, look at Animated Polka Dot Pattern instead.