What is desktop publishing?
Desktop publishing (DTP) means making a printed or on-screen document on a computer by placing text and pictures exactly where you want them.
A word processor is built for writing. A DTP program is built for layout, which means where each thing sits on the page. Popular programs are Scribus, Adobe InDesign, Affinity Publisher and Canva. The ideas are the same in all of them.
DTP is used for leaflets, posters, books, magazines, menus, cards and e-books.
Page setup: size, margins and columns
First choose the page size (A4, A5, letter, or a custom size) and the orientation (portrait is tall, landscape is wide).
Margins are empty borders around the page. They keep text away from the edge so nothing is cut off and the page can breathe.
Columns divide the width into vertical strips. Short lines are easier to read than very long ones, so newspapers and magazines use several columns. The small gap between two columns is the gutter.
A grid is the set of guides (margins, columns, rows). If every page uses the same grid, the whole document looks neat.
Master pages hold things that repeat on every page, such as page numbers, a header with the title, or a footer with the date. You draw them once and they appear everywhere.
Frames and layers: text, pictures and shapes
In DTP everything sits in a frame (a box). A text frame holds words and a picture frame holds an image. Text frames can be linked: when one is full, the extra text flows into the next one, even on another page.
Objects sit in layers. The one on top hides what is below it. You can send an object backward or bring it forward. Putting text over a photo needs the text layer above the photo layer.
Text wrap makes text flow around a picture instead of going under it.
Pictures come in two kinds. A bitmap (JPG, PNG) is made of pixels; if you stretch it too much it looks blurry. A vector (SVG, PDF, logo) is made of lines and curves; it stays sharp at any size. For printing, a photo should be about 300 dpi at its final size.
Type and colour: making a page easy to read
Use levels of text: a headline (about 30 to 40 pt), a subheading (about 16 to 20 pt) and body text (about 9 to 12 pt). The size difference tells the reader what to read first. This is called hierarchy.
Do not use more than two or three fonts. A common pair is one serif font for body text and one sans-serif font for headings. Keep enough line spacing (leading) and use alignment consistently (left-aligned text is easiest to read).
Colour: choose a few colours that go together. Make sure text and background have strong contrast (dark text on a light background, or the reverse). Do not put light grey text on white.
Brand identity: a business or school repeats the same logo, colours and fonts everywhere. The rules are written in a brand book (style guide), so every poster, card and web page looks like it belongs together. A good logo is simple, works in one colour and stays clear when small.
Getting ready for print
Colour modes. Screens make colour with light: RGB (red, green, blue). Printers make colour with ink: CMYK (cyan, magenta, yellow and K = black). Some bright screen colours cannot be printed, so design print jobs in CMYK from the start.
Bleed. A trimming machine is never perfect. If a picture stops exactly at the page edge, a thin white line may show. So the picture is extended about 3 mm past the edge. This extra part is the bleed and it is cut off.
Crop marks are small lines in the corners that show where to cut. Important text should stay at least 5 mm inside the edge (the safe zone).
Resolution: 300 dpi for print, 72 to 150 dpi for screens.
Export: make a PDF with fonts embedded. Check it once (this is called preflight) before sending it to the printer. Printing on a large scale is called offset printing; for a few copies digital printing is cheaper.
Common formats: leaflet, booklet, magazine, e-book
Leaflet (flyer): one sheet, often folded in three. Each panel has a job: the front is the cover that catches the eye, the inside gives details, the back gives contact information.
Booklet: pages folded and joined in the middle. The total number of pages must be a multiple of four. Leave a little extra space at the spine so the text does not vanish into the fold.
Magazine: a strong grid, big pictures, a headline, several columns and a pull quote (a short quote shown large). Page numbers and section names sit in the same place on every page.
E-book: made for screens (EPUB or PDF). In EPUB the text reflows: it re-arranges itself to fit a phone or a tablet, and the reader can change the font size. So you do not fix exact positions, you set styles (heading, paragraph) instead.
Mail merge is a related idea: one letter template plus a list of names creates many personal letters automatically.
Try it: design a one-page poster at home
- Take a sheet of paper and draw a border 1 cm from the edge. That is your margin.
- Divide the page into two columns with a pencil line.
- Cut a picture from an old magazine and stick it in the top part.
- Write a big headline, a medium subheading and small lines of text. Compare the three sizes.
- Look at it from 2 metres away. Can you still read the headline? If yes, your hierarchy works.
Then do the same on a computer in Scribus or Canva and print it.
Key formulas and definitions
- Key term: DTP = desktop publishing = layout of text and pictures on a computer
- Key term: margin = empty border; gutter = gap between columns; grid = guides for the page
- Key term: bleed (about 3 mm) = picture extended past the cut line
- Key term: RGB for screens, CMYK for print
- Photo resolution: about 300 dpi for print, 72 to 150 dpi for screen
- Booklet pages = a multiple of 4
- Pixels needed = size in inches × dpi (for example 4 in × 300 dpi = 1200 px)
Worked examples
1. A poster is A4 (210 mm × 297 mm). With 3 mm bleed on every side, what size must the artwork be?
Add 3 mm on both sides of each direction. Width = 210 + 3 + 3 = 216 mm. Height = 297 + 3 + 3 = 303 mm.
2. You want to print a photo 4 inches wide at 300 dpi. How many pixels wide must the photo be?
Pixels = inches × dpi = 4 × 300 = 1200 pixels.
3. A school magazine has 10 pages of content. How many pages should the booklet have if the number must be a multiple of 4?
The next multiple of 4 above 10 is 12. So the booklet needs 12 pages and the last 2 can hold notices or be blank.
4. A page has width 210 mm, margins of 20 mm on each side and 2 columns with a 6 mm gutter. How wide is each column?
Usable width = 210 - 20 - 20 = 170 mm. Take away one gutter: 170 - 6 = 164 mm. Two columns share it: 164 ÷ 2 = 82 mm each.
5. A logo looks perfect on screen but blurry on a large banner. What kind of file was it likely, and what is the fix?
It was a bitmap (for example a small JPG), made of pixels. Stretching shows the pixels. The fix is to use the vector version of the logo (SVG or PDF), which stays sharp at any size.
6. A 3-fold leaflet is printed on a landscape A4 sheet (297 mm wide). About how wide is each panel?
297 ÷ 3 = 99 mm per panel. In practice one panel is made a little narrower (about 2 mm) so it folds inside the others.
Common mistakes
- Putting text very close to the edge. It can be cut off. Keep text inside the margin and the safe zone.
- Using too many fonts and colours. Two fonts and a few colours look better than ten.
- Using a small web image for print. At 72 dpi it prints blurry; use about 300 dpi at the final size.
- Forgetting bleed. A background colour that stops at the edge can leave a white line after cutting.
- Designing in RGB for print. Some bright screen colours look dull in CMYK. Check in CMYK early.