Halftone and print

Halftone dot screens, comic-book pop grunge, manga screentone and a set of print-damage effects (photocopy, misprint, fold, dust and scratches), plus the print finish pass that makes every export feel printed. Each section lists the parameters exactly as the controls show them.

Halftone

A halftone screen is how printers have reproduced photos for over a century: the image is broken into a grid of dots, and each dot grows or shrinks with the tone underneath it. Bitgrain's halftone rotates a grid over your image, samples the color at the center of each grid cell, and draws a dot sized to match.

Halftone is the image editor's default effect. Open it with the halftone button. The popover has an on/off switch at the top (labelled "Halftone, Dot-screen print effect"), then Screen Style, Controls and the Invert ink switch.

Screen styles

Mono and Colour. Dot size follows the luminance of the sampled spot. With Invert ink off, dots are light on a black ground and grow in the highlights. With it on (the popover describes it as "Dark dots on white bg"), dots are dark on a white ground and grow in the shadows, like newsprint.

CMYK. This style separates each sampled color into cyan, magenta, yellow and black, then draws each ink on its own screen at the traditional offset-printing angles: cyan at 15°, magenta at 75°, yellow at 0° and black at 45°. The inks multiply where they overlap, just like real ink, and the rotated screens create the soft rosette pattern you see in magazines under a loupe. Black is printed slightly lighter and the color inks slightly stronger, to keep shadows from turning to mud.

Note: In CMYK style the Angle slider and Invert ink have no effect, because each ink uses its fixed angle on white paper. CMYK also uses a minimum cell size of 3 px, so four screens have room to show.

Halftone parameters

Image editor, in the halftone popover:

Video editor, on the Halftone effect: Mono, Color and CMYK buttons, Round and Square, Cell size 2 to 32 px (default 2), Angle 0 to 90 (default 45), Intensity 0.1 to 3 (default 1), Sharpness 0 to 100 (default 60), Invert Dots (off), and Jitter. The style starts on Mono.

Studio, under Bitgrain effects, Halftone:

Studio has no Dot shape or Sharpness control, so dots are always round at sharpness 60.

Tip: Cell size is measured in working-grid pixels, so it interacts with Resolution in the adjust popover. Lower the Resolution and each dot covers more of your photo. Use both together to find the dot scale you want.

Motion jitter in video

In the video editor, the halftone Jitter box can make the screen shimmer over time. At 0 hz (the default) the dots stay perfectly still. Above 0, the screen angle wobbles very slightly (a fraction of a degree) at that frequency, which reads like a live print or a projected film. AUTO ties the frequency to how much is moving on screen. See frame seeds and jitter.

Dot matrix

Dot matrix redraws the image as evenly spaced round dots, like an LED sign. Each dot sits on a pitch of six working-grid cells and takes the average color of the area under it (or its brightness, when colorize is off), and the gaps between dots stay near black. It has no parameters.

In the image editor, pick Dot matrix from the filters list. The /halftone landing page also opens the editor with it selected. Lower Resolution for bigger, fewer dots.

Pop grunge

Pop grunge is a comic-book halftone with attitude. It pushes the image through a hard contrast curve, draws dots in one ink color on one paper color, jitters each dot's size a little, then sprinkles grain and ink spatter over the top. Think screen-printed gig posters and photocopied zines.

In the image editor, open artistic and choose pop grunge ("comic dot ink"). The popover has an on/off switch ("Pop Grunge, Halftone with grit"), then Theme, Custom Colors and Controls.

Themes set the ink and paper pair in one click:

Custom Colors has an Ink and a Paper color picker if none of the themes fit.

How it behaves: dot area grows with darkness, so dots merge into solid ink in the shadows. Each dot's size varies slightly on its own, so the screen looks hand-pulled rather than digital. The speckle and grain come from a fixed hash, so the same settings always give the same result.

In the video editor the effect is called Pop Grunge. It has four themes (Comic, Noir, Sun, Acid), Ink and Paper pickers, Dot size 2 to 28 px (default 2), Angle 0 to 90 (30), Threshold 0.1 to 0.9 (0.55), Grain (0.35), Spatter (0.45) and Jitter, which defaults to 30 hz so the texture boils like printed film.

In Studio it is Pop art, with Cell 2 to 200 (2), Angle 0 to 360 (45) and Threshold 0 to 1 (0.5). It uses red ink on black paper with the default grain and spatter.

Manga

Manga redraws your image as black-and-white screentone hatching with inked outlines, like a printed comic page.

It builds the picture in three parts:

1. Hatching. Up to four layers of parallel strokes, at your angle, then rotated 90°, 45° and -45° from it. Each layer only appears once the tone is dark enough, so light areas get single hatching and shadows get dense cross-hatching. Strokes wobble slightly and break up with pen pressure, so they look drawn.
2. Solid blacks. The very darkest areas fill in solid.
3. Outlines. An edge-finding pass draws ink lines that follow the shapes in your photo.

In the image editor, open artistic and choose manga ("crosshatch, inked lines").

Tip: Manga loves strong, simple lighting. Raise Contrast in the adjust popover before you tune the hatching, and try a larger Hatch gap at high Resolution so strokes stay visible.

Photocopy

Photocopy imitates a page run through a tired office copier: color drops away, the tones are slammed toward pure black and white, and only a narrow band of greys survives around the cut point.

Available in the video editor and Studio.

At very high Contrast the result is effectively a threshold stencil. Around 3 to 5 you keep some toner grey.

Misprint

Misprint slides the red and blue channels in opposite directions while green stays put, like a press whose plates have drifted out of register. Edges pick up colored fringes, and flat areas stay clean.

Available in the video editor and Studio.

Fold

Fold adds the creases of a folded poster: thin highlight and shadow lines, evenly spaced across both directions of the image, as if light is catching the ridges of the paper.

Available in the video editor and Studio.

Dust and scratches

Dust and scratches lays analog wear over the image: tiny white and black specks, and long vertical scratches that wander slightly as they run, like a well-played film print or a dusty scan.

Available in the video editor (as Dust & Scratches) and Studio (as Dust & scratches).

Tip: If a scratch lands across a face, change Seed until the layout suits the picture. Nothing else changes.

Print finish

Print finish is not an effect you pick. It is a final pass that runs over the whole result, designed to take the flat, too-perfect edge off digital output so it reads like something printed on paper.

In the image editor it lives at the bottom of the adjust popover as Print finish ("Paper grain, ink tone, soft edges"). It is on by default.

What it does, in order:

1. Ink and paper tone. The deepest shadows are lifted toward a warm newsprint black instead of pure digital black, and the brightest highlights are tinted toward the paper color. Color is muted very slightly.
2. Paper mottle. A soft, low-frequency blotchiness of a few percent, like uneven ink absorption.
3. Misregistration. On larger images, the red and blue channels are nudged 1 px apart.
4. Grain. Fine grain, heavier in the shadows than in the highlights.

A few rules about where it applies:

• It is skipped for ASCII and braille, which are meant to look like clean type.
• On export, it is applied after the image is scaled to its final size, so the grain is fine and even at any export size rather than blown up.
• Studio's Bitgrain effects also apply it, using the same on or off setting and strength as the image editor.
• The grain and mottle come from a seeded generator, so the same look gives the same texture on every export.
• PNG downloads still follow the export panel's colors slider. Set it to 100 (full color) to keep every grain.

Tip: Turn Print finish off for pixel art and anything you want mathematically clean. Lower it to around 40% if you want a hint of paper without visible grain.

Related

• Effects overview
• Dithering
• Risograph separations
• Creative effects
• Studio effects and adjustment layers
• Video effects and overlays

More documentation

• All documentation
• More in effects
• Open the editor
• Open the studio
• Read the blog