LineScreen | GlitchNodes

LineScreen converts an image into a halftone-ish line pattern - the kind of engraved-lines look you associate with old newspaper photos and banknotes. It's one of the quieter nodes in GlitchNodes, but it's also one of the most reliable: no randomness, no fragile file I/O, just a clean, mechanical effect with a satisfying print-shop feel. Reach for it when you want a poster treatment or a stylistic break from all the noise-based glitch stuff.

Mechanically it's simple and robust. The node builds a repeating line pattern (via Pillow's ImageDraw) at a given angle and line_spacing, then applies it to the image using a brightness threshold: areas below the threshold show the line pattern, and contrast_boost sharpens the decision before it's made. You control the two colors directly - line_color_r/g/b (default black) and bg_color_r/g/b (default white) - so the whole thing is a two-color screened engraving. invert flips which areas get the lines.

The inputs that matter

• line_spacing (2–20, default 4) - distance between lines. Low = dense, high = coarse. This is the primary texture knob.
• angle (-90 to 90, default -45) - the line direction. -45/45 degrees is the classic halftone; 0 and 90 give horizontal/vertical rulings.
• threshold (0.1–0.9, default 0.5) - brightness cutoff that decides where lines appear. Crank it up and more of the image fills with pattern.
• contrast_boost (1.0–2.0, default 1.2) - punch up the source contrast before screening, which gives crisper line edges.
• invert - flip the pattern/background roles.
• line_color / bg_color (each R/G/B 0–1) - your two-color palette. Two-color design, done.

Output is image (IMAGE) → PreviewImage/SaveImage. Input is named image and it handles batches.

Installing it

Standard GlitchNodes install:

cd ComfyUI/custom_nodes
git clone https://github.com/pxl-pshr/GlitchNodes
# restart ComfyUI

or ComfyUI Manager → Install Custom Nodes → search "GlitchNodes". Deps: numpy, torch, Pillow, opencv-python, scipy. No models, no downloads beyond the pack.

Gotchas

The main beginner trap is expecting the image's own colors to survive - LineScreen reduces everything to two flat colors, so if you pick a black line on white background, your full-color render becomes a black-and-white engraving. That's the design, not a bug; pick your two colors deliberately (a dark magenta line on cream reads especially well). Also, threshold interacts with contrast_boost: if the pattern looks "dusty" or noisy, raise contrast_boost and nudge the threshold rather than fighting the spacing. And as always with this pack, "highly experimental and may break or even error" - though in practice LineScreen is one of the calmest, most predictable nodes here.