# What is a rasterbated poster? How halftone dot wall art works

Source: https://spolvero.design/articles/what-is-a-rasterbated-poster/
Updated: 2026-09-23
Tool: https://spolvero.design/tools/print/rasterbator-poster/

> A rasterbated poster is a photo rebuilt from a regular grid of dots, each one larger where the picture is dark and smaller where it is light, then printed across many sheets of paper. Up close it looks like a pattern; from across a room the dots merge back into the photo. Because each dot needs only one pixel, even a small photo makes a wall-sized poster. For most rooms, 8 to 15 mm dots work well.

Walk up to a rasterbated poster and it is just dots: big ones, small ones, in a neat grid. Walk to the other side of the room and a face appears. That trick is why the style has stayed popular for twenty years. It is also cheap: black dots on ordinary paper, printed at home.

## How halftone works

Printers cannot print grey. They can only put ink down or leave paper bare. Halftone solves this with dots. A dark area gets large dots that nearly touch; a light area gets small dots with lots of white between them. From far enough away, your eye blends the dots and the white into shades of grey.

Newspapers have used halftone for more than a century, with dots too small to notice. A rasterbated poster uses the same idea with dots you can see from across the room, and prints the result across many sheets. The name comes from The Rasterbator, a program from the mid-2000s that made the style popular. The Spolvero tool is not affiliated with it.

## Why small photos work

A normal photo poster needs a lot of pixels. Blow a small photo up to a metre wide and it turns soft and blocky. A dot poster does not have that problem. Each dot only needs one pixel from the photo, to decide how big the dot should be. The dot itself is drawn as a vector circle, so it prints sharp at any size.

So a photo 300 pixels wide is already enough for a poster 300 dots across. At 10 mm dots, that is three metres. A photo from a chat app, too small for a normal poster, is fine here.

## Choosing the dot size

Dot size decides how far away the picture appears.

| Dot size | Best seen from | Look |
| --- | --- | --- |
| 5 to 8 mm | 1 to 2 metres | Closer to the photo, more sheets for the same detail |
| 8 to 15 mm | 2 to 3 metres | The classic look for a living room wall |
| 15 mm and up | 3 metres or more | Bold and graphic, reads as pattern up close |

Smaller dots keep more detail but need more paper to show it. Larger dots make fewer, bolder shapes. The [rasterbator poster maker](/tools/print/rasterbator-poster/) shows a preview at size as you change it.

## Black or colour?

- **Black dots** are the classic look. They are the most striking and need only black ink, usually the cheapest cartridge.
- **Colour dots** take each area's own colour. They suit bright pictures.
- **A custom colour** prints the whole poster in one ink. Try it on pastel paper for a screen-printed look.

The tool estimates the ink before you print, in standard pages, the unit cartridge yields are quoted in.

## Which photos work

Contrast is everything:

- **Faces with light from one side.** The shadow side becomes large dots, the lit side small ones.
- **Silhouettes and bold shapes** on a plain background.
- **Album covers and film stills** with dark backgrounds.

Avoid busy, evenly lit scenes, such as a crowd or a landscape in flat light. They turn into an even grey field of dots with nothing to pick out. Crop close: a face that fills the frame reads better than a figure in a wide shot.

## Printing and hanging

1. Add the photo, switch the style to dots, and choose the dot size and colour.
2. Set the width in sheets, centimetres or inches.
3. Download the PDF. Every sheet is labelled: rows are letters from the top, columns numbers from the left.
4. Print at 100% or "Actual size", never "Fit to page", which shrinks each sheet slightly and stops the dots lining up.
5. Trim the left and top edge of each sheet along the marks, and lay it over its neighbour's overlap strip. Dots that cross a join line up exactly.

The picture is read and turned into the PDF in your own browser, so it is never uploaded.

For paper choice, glue and hiding the seams, see [how to print a large poster on A4](/articles/print-large-poster-on-a4/). For a normal photo poster rather than dots, the [poster maker](/tools/print/poster-maker/) prints the photo itself, and [how big can I print a photo](/articles/how-big-can-i-print-a-photo/) tells you how large it can go before it blurs.

## Questions

### What is a rasterbated poster?

A picture rebuilt from a grid of dots sized by how dark each part is, printed across several sheets to make wall art. It is the halftone technique newspapers use, enlarged. The name comes from The Rasterbator, a program from the mid-2000s that made the style popular.

### What dot size is best for a halftone poster?

Choose by viewing distance. For a poster seen from two to three metres, 8 to 15 mm dots work well. Smaller dots keep more detail but need more sheets; larger dots look more graphic.

### Does a dot poster need a high-resolution photo?

No. Each dot needs only one pixel of the photo, so a picture 300 pixels wide is enough for a poster 300 dots across, which is three metres at 10 mm dots. The dots are drawn as vector shapes and print sharp at any size.

### Which photos work best as dot posters?

Photos with strong contrast: faces lit from one side, silhouettes, bold shapes and dark backgrounds. Busy, evenly lit scenes turn into an even field of grey dots.