Apply classic halftone dot-matrix effects to any image. Adjust dot size and density. Perfect for print-inspired and comic book aesthetics.
A halftone turns continuous tone into dots of varying size. Hold a printed magazine photograph close enough and the illusion falls apart: there is no grey ink, only black dots that grow fatter in the shadows and shrink to nothing in the highlights. Every offset press, every newspaper, every screen printed t-shirt works this way, because ink is either on the paper or it is not. Halftoning is the translation layer between a photograph and a printing press.
Three numbers describe any halftone screen, and getting them right is most of the work.
Screen frequency, measured in lines per inch, sets how many rows of dots fit across the image. Newsprint runs coarse, around 85 lpi, which is why old newspaper photographs have that visible dotty texture. Glossy magazines run 150 lpi or higher and read as continuous tone at arm's length. Coarse screens are the expressive choice: you can see the mechanism, and that visible mechanism is most of the appeal.
Dot size is derived from the tone underneath. A pixel at 90 percent black grows a dot that nearly fills its cell; a pixel at 10 percent leaves a pinprick. The dots sit on a fixed grid, so what varies is area, not position.
Screen angle matters as soon as you have more than one ink. Two screens laid down at the same angle interfere and produce a moire pattern, a coarse ugly plaid that no amount of retouching fixes. The printing industry settled on offsetting each ink by fifteen or thirty degrees, with black at 45 degrees because the eye is least sensitive to diagonal structure there.
Bitgrain runs halftones in three modes, and they are genuinely different processes rather than presets on the same one.
Mono halftone reduces the image to a single ink on paper. One screen, one angle, maximum contrast. This is the mode for screen printing, risograph, photocopier zines and anything that will be reproduced with a single pass.
Colour halftone screens each RGB channel separately and overlays the results, which gives you the pop art look: visible coloured rosettes, deliberately imperfect registration, comic book energy.
CMYK separation is the production mode. The image is converted into four channels of cyan, magenta, yellow and black, each screened at its own conventional angle, and exported as four layers. That is what a commercial printer actually needs. It is not a filter that looks like CMYK, it is the same decomposition a prepress operator would produce.
Round dots are the default and the most neutral. They grow smoothly from highlight to shadow and only touch their neighbours in the deep tones.
Square dots meet edge to edge at fifty percent, which produces a sudden visual jump called dot gain shift. Designers exploit it: the midtones snap harder and the image gains a graphic, poster-like quality.
Line screens replace dots with thickening rules and read as engraving or as a deliberately mechanical treatment. Elliptical dots split the difference and are common in fine art reproduction because they delay the midtone jump.
Bitgrain also carries crosshatch and manga screentone modes, which are halftone relatives rather than halftones proper. Screentone in particular uses fixed density patterns from a library rather than continuously varying dot area, which is exactly how it was applied by hand with adhesive sheets before digital comics.
Halftoning destroys tonal subtlety by design, so the preparation matters more than the halftone settings.
Raise contrast until the image looks slightly too punchy on screen. What survives the screen is roughly the middle sixty percent of your tonal range, so anything sitting in the deep shadows will simply fill in solid and anything near white will drop out entirely.
Sharpen before, never after. A halftone screen applied to a soft image produces soft dots, and no amount of post-sharpening recovers the edge because the edge information is gone.
Check the result at print size rather than at screen zoom. A screen that looks perfect at 200 percent zoom will disappear completely on a 300 dpi print, and one that looks reasonable on a monitor may be far too coarse for an A6 flyer.
Everything runs locally in the browser, and the same settings always produce the same screen, so a project you hand to a printer today reproduces identically six months later.
A halftone varies the size of dots on a fixed grid. A dither keeps dot size constant and varies how many dots appear in an area. Halftones come from the printing tradition and read as ink on paper; dithers come from limited displays and read as digital.
For a visible, expressive halftone, go coarse: think newsprint rather than magazine. For work that needs to read as a normal photograph in print, go fine. If you are sending the file to a commercial printer, ask them what line screen their press runs.
That is moire, caused by two screens sitting at the same or nearly the same angle. Offset each ink by fifteen to thirty degrees. Bitgrain applies conventional angles automatically in CMYK mode.
Yes. CMYK mode exports four screened channels as separate layers, and risograph mode exports per-ink layers as a ZIP. These are production files, not a flattened effect.