Using PNG images for print: resolution, DPI and size explained

An image that looks sharp on screen can print blurry, pixelated or much smaller than expected. Almost always, the reason is resolution. This guide explains what DPI means, how many pixels you actually need, and how to check a transparent PNG before you send a design to the printer.

Pixels, inches and DPI

A PNG has a fixed number of pixels, for example 2000 × 1500. On screen, those pixels are simply displayed. On paper, they have to be spread over a physical size.

DPI (dots per inch), often used interchangeably with PPI (pixels per inch), says how densely the pixels are packed when printed:

• At 300 DPI, 2000 pixels print 6.7 inches (about 17 cm) wide.
• At 150 DPI, the same 2000 pixels print 13.3 inches (about 34 cm) wide, but each pixel is twice as large.

The DPI value stored inside the file does not change the number of pixels. It is only an instruction. What matters is pixels divided by printed size.

How many pixels do you need?

The formula is simple:

pixels needed = printed size in inches × DPI

or, in centimetres:

pixels needed = printed size in cm ÷ 2.54 × DPI

Common targets:

Use	Typical DPI	Example
Flyers, menus, brochures held in the hand	300	8 cm wide → 945 px
Posters viewed from a metre or more	150–200	40 cm wide → 2,360 px at 150 DPI
Large banners and roll-ups viewed from a distance	72–100	80 cm wide → 2,270 px at 72 DPI
School worksheets and office print-outs	150–200	6 cm wide → 470 px at 200 DPI

The further away people stand, the lower the DPI you can get away with. A roll-up banner seen from three metres does not need the same density as a business card.

Check a PNG before printing

On pngtop, every image page lists the dimensions in pixels. Divide the width by the size you plan to print to see the effective DPI:

• 1200 px printed 10 cm (3.94 in) wide → about 305 DPI. Good for close viewing.
• 600 px printed 10 cm wide → about 152 DPI. Fine for a poster, soft on a flyer.
• 300 px printed 10 cm wide → about 76 DPI. Visibly blurry up close.

Design tools help too:

• Canva warns about low-resolution images when you download as PDF Print.
• Photoshop: Image → Image Size, untick Resample, and type the print size. The resolution field shows the real DPI.
• Word and PowerPoint do not warn you, so check the numbers yourself.

Can you make a small PNG bigger?

You can enlarge an image, but you cannot add detail that was never captured. Standard resizing creates soft edges. AI upscalers can produce more convincing results for simple subjects, but they may invent details or distort text and faces. Always inspect an upscaled image at 100 percent before printing.

The better option is to choose a larger source image from the start. Our collections show the larger, higher-quality images first.

Transparency in print

Printers handle transparency differently from screens:

• PDF is the safest format to send. Export your design as PDF Print (Canva) or PDF/X (Adobe), which keeps transparent areas correct.
• Flattening problems. Some older printing workflows flatten transparency and can produce thin white lines or boxes around PNGs. Ask the printer for a proof if your design has many overlapping transparent images.
• White halos show more on paper. A faint white edge invisible on screen can print as a clear outline on a dark background. Our guide to removing white edges explains how to clean it.
• Shadows may print darker. Soft drop shadows often come out heavier on paper. Reduce their opacity slightly for print versions.

Colour: RGB vs CMYK

PNGs are always RGB, the colour model of screens. Printers use CMYK inks, which cannot reproduce some bright RGB colours, especially vivid greens, blues and oranges.

• Expect very saturated colours to print a little duller.
• If colour is critical, such as a brand colour, ask your printer for a proof.
• Professional layout tools can convert to CMYK and preview the result; Canva Pro offers a CMYK option for PDF Print.

File size and printing

Large PNGs make big design files, which can slow down online printing services. If an image will print small, reduce it to the pixels you actually need using the formula above. Our guide to optimizing PNG file size shows how to shrink files without visible loss.

Common mistakes

• Using an image that looks fine on a phone screen but is only a few hundred pixels wide.
• Changing the DPI value in the file and assuming the image is now "high resolution".
• Stretching a PNG non-proportionally to fill a space.
• Forgetting bleed: extend backgrounds 3 mm past the trim line.
• Sending a JPG of the design instead of a PDF, which loses sharp text and transparency.

Quick checklist

1. Decide the printed size of each image.
2. Multiply by the DPI you need (300 for hand-held, 150 for posters).
3. Check the PNG has at least that many pixels.
4. Export as PDF for print, with bleed.
5. Ask for a proof when colour or fine detail matters.

A minute spent on this arithmetic before printing saves reprints, and makes sure the transparent images you chose look as sharp on paper as they do on screen.