Checkerboard 🏁

Despite the name, this isn't just a checkerboard generator - it's a small procedural pattern engine with 21 pattern types under the hood, checkerboard being the most literal one. It's the kind of node you reach for when you need something in a slot that isn't a real photo: a placeholder background behind a composite while you're building a workflow, a test card for checking how a node handles color and contrast, or the classic transparency-indicator checkerboard behind something you're testing alpha compositing on.

How it works

You set a canvas size and a grid shape (rows × cols), pick a pattern, and it renders. The pattern list covers a lot more ground than the node's name suggests - straight checkerboard, horizontal/vertical/diagonal stripes, rings, cross, plus, "portal," vertical and horizontal gradients, and more beyond what's visible in a quick glance at the dropdown. is_colored switches between plain black-and-white and randomly colored cells, and seed controls whichever randomness the chosen pattern uses - the color assignment on a colored pattern, or the exact look of random/random uniform (the actual default pattern, worth noting - not the fixed checkerboard pattern most people would assume from the node's name).

The node also outputs a MASK alongside the IMAGE, which means you get a ready-made mask matching the pattern for free - genuinely useful for patterns like "cross" or "plus" if you want a structured mask shape without drawing one by hand.

The inputs and outputs that matter

• width / height - 256 to 8192, both default 1024.
• rows / cols - grid density, 1 to 128 each, both default 9.
• pattern - 21 choices, default random uniform (not plain checkerboard).
• is_colored - boolean, default false (black and white).
• seed - 0 to 4095, drives the pattern's randomness.

Outputs: IMAGE and MASK, both matching the generated pattern.

Installing it

Via ComfyUI Manager: search "iTools" or "ComfyUI-iTools," install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/MohammadAboulEla/ComfyUI-iTools

then restart.

Troubleshooting

You expected a plain checkerboard and got something else. The default pattern is random uniform, not checkerboard - the node's name is a description of its general category, not its default output. Explicitly set pattern to checkerboard if that's specifically what you want.

Pattern looks the same on every run. If seed is fixed, any randomness in the chosen pattern (color assignment, the truly random pattern option specifically) will repeat. Randomize or increment the seed if you want variation run to run.

High rows/cols values are slow or produce a busy result. Both go up to 128, which at a 1024×1024 canvas means very small cells - fine for a fine-grained test pattern, but likely more detail than you want for something like a simple transparency-indicator background. Lower single-digit values (the defaults are 9×9) read much more like the classic checkerboard look.

MASK output isn't what you expected. It follows whatever pattern you picked, not a fixed checkerboard shape - a stripe or gradient pattern produces a correspondingly different mask, not a generic checkered one, so check that your chosen pattern actually produces the mask shape you're after before wiring it somewhere that expects specific geometry.