Dithering explained: threshold, patterns and when to use it
What dithering does to a photo, why the threshold matters more than it looks, why the effect must be made at final size, how to colour it afterwards, and the one-click tool with a live example.
Beginner3 min readUpdated 27 September 2026Dither tool · Effects
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What the threshold does
Every pixel is compared with the threshold: brighter goes white, darker goes black, and the difference between the real value and the choice is pushed onto the pixels to the right and below (that is the Floyd-Steinberg part). A low threshold keeps more of the image bright, so only true shadows fill with black; a high threshold pushes midtones dark and the image becomes mostly pattern. Portraits usually sit a little below the middle; graphic, high-contrast subjects can go higher.
Make it at final size
Because the pattern is one pixel fine, it belongs to a particular pixel size. Scale a dithered image up and the pixels become soft blocks; scale it down and the pattern collapses into grey mush or moiré. Decide where the image will be seen, make the dither at that exact pixel size, and export as PNG, which keeps every pixel. JPG compression smears the pattern.
Colour it afterwards
The result is black and white. In the Editor, a colour layer above it set to Screen colours the black pixels; set to Multiply it colours the white ones. A dark green dither on a pale green field is the handheld-console look; black on cream is the zine look. Blend modes and opacity explains the two.
How to do it in Voidcanvas
- Open the Dither tool and drop in a photo, or use the sample that is already loaded.
- Move Threshold under Adjust until the balance is right.
- Press Download PNG for the full-size file, or Send to Layer Stack to open the Editor with the dither as a live filter layer you can colour, mask and combine.
- In the Editor and in Effects the same effect is Dither under Artistic.
Common mistakes
- Grey soup. Low-contrast photo. Fix the contrast first, then dither.
- Blurry pattern. Exported as JPG, or scaled after the fact. PNG, at final size.
- Too fine to notice. A 4000 px photo dithered at full size looks like a photo. Reduce it to the display size first.
Dithering or halftone?
Halftone puts dots of varying size on a regular grid and reads as print. Dithering scatters single pixels and reads as an early screen. Halftone survives scaling better; dithering is sharper at small sizes.
Can I dither in colour?
The effect itself is black and white. Colour it afterwards with a blend mode, or tint the photo with Duotone first and set the dither layer to Multiply.