Beginner level · Module 4: Print and Digital Formats · Lesson 1 of 3
Colour Modes and Resolution
Choose settings that match where the design will be seen.
In this lesson you will
- Choose RGB or CMYK
- Calculate the pixels needed for print
Key concepts
RGBCMYKDPI and PPIvector and raster
The lesson
Screens mix light (RGB); printers mix ink (CMYK). Bright RGB colours can look duller in print, so check CMYK values for print work.
Print needs about 300 pixels per inch at final size; screens need far fewer. A photo that looks fine on a phone may print blurry.
Vector graphics (logos, icons) scale to any size; raster images (photos) have fixed pixels.
Step by step
- Check the colour mode of a document.
- Calculate pixels needed for an A5 print.
- Check a photo's resolution.
- Decide which elements should be vector.
How many pixels does a print need?
Working out image sizes for an A5 flyer and a roll-up banner.
| Item | Working | Amount |
|---|---|---|
| A5 flyer with 3 mm bleed: 154 × 216 mm at 300 ppi | 154 ÷ 25.4 × 300; 216 ÷ 25.4 × 300 | 1,819 × 2,551 px |
| Same flyer from a 72 ppi web image (148 × 210 mm) | 148 ÷ 25.4 × 72; 210 ÷ 25.4 × 72 | 420 × 595 px — too small |
| Roll-up banner 850 × 2,000 mm at 100 ppi | 850 ÷ 25.4 × 100; 2,000 ÷ 25.4 × 100 | 3,346 × 7,874 px |
Explanation
A photo downloaded at web size has about a quarter of the pixels needed in each direction for the flyer, so it would print blurred.
The banner is viewed from metres away, so 100 ppi at full size is usually enough — always confirm with the printer's specification.
Check your understanding
1 inch = 25.4 mm; 154 ÷ 25.4 = 6.06 inches × 300 = 1,819 px.
Practice activity
Check the flyer's images and colour settings for print.
Expected result: A flyer with suitable resolution and colour settings.
Check your understanding
-
Which colour mode do printers use?
Show answer
CMYK.
-
What resolution is usually needed for print?
Show answer
About 300 pixels per inch at final size.
Taught live by an instructor — online or in person. Free course lessons are for self-study and do not lead to a certificate — see registration options.