Troubleshooting

Improve fax quality

Tips for crisp and easily readable faxes

Tested solutions

Quick fix

Quick diagnosis

Quick tip

Low resolution, incorrect format or poor contrast

Use PDF format, choose high contrast (black text on white background), font size at least 10 pt.

Quick check

Check these points first

Document saved as PDF?
Black text on white background?
Font size at least 10 pt?
Resolution at least 200 DPI?
Sufficient margins (min. 1,5 cm)?

Possible causes and solutions

Click a cause to see the solution

1

Text is blurry or pixelated

Cause

Resolution too low or compressed image

Symptoms

Letters are difficult to read, edges are not sharp

Solution

Create the document with at least 200 DPI. Use PDF instead of JPEG for text documents.

2

Greys are too dark or too light

Cause

Fax machines can only reproduce a limited range of greys

Symptoms

Photos or graphics are barely recognisable

Solution

Increase the contrast. Faxes work best with black and white documents. Avoid photos or convert them into high-contrast graphics.

3

Margins are cut off

Cause

Page margins too small, recipient fax machine prints with different margins

Symptoms

Text at the page edge is missing

Solution

Use page margins of at least 1,5 cm on all sides. Do not place important information at the very edge.

4

Font too small to read

Cause

Font size under 10 pt, fine details are lost

Symptoms

Text is illegible after faxing

Solution

Use at least 10 pt font size, ideally 12 pt. Avoid thin or ornate fonts.

How to avoid the problem

PDF is the best format for faxes - formatting is preserved and quality is optimal.
Avoid coloured backgrounds - faxes are transmitted in black and white.
Scan paper documents at a minimum of 200 DPI in black and white.

A clearly legible fax creates a professional impression. With these tips you can ensure that your faxes reach the recipient in optimal quality.

The optimal document

For the best fax quality, your document should have these characteristics:

Format: PDF preferred
Contrast: Black text on white background
Font size: At least 10 pt, ideally 12 pt
Font: Clear, easily legible font (Arial, Times New Roman)
Resolution: 200-300 DPI

Scanning paper documents correctly

If you want to fax a paper document:

Scan mode: Black and white or greyscale (not colour)
Resolution: 200 DPI minimum, 300 DPI for best quality
Format: Save as PDF
Alignment: Place straight, skewed scans are harder to read

Avoid common mistakes

These mistakes often lead to poor fax quality:

Coloured backgrounds: Often become too dark or illegible
Photos: Usually come out poorly - avoid if possible
Small text: Anything under 10 pt becomes hard to read
Thin lines: May disappear or appear broken

Frequently asked questions

Which file format delivers the best fax quality?

PDF delivers the best quality for faxes. The format preserves formatting, fonts and layout exactly. JPG and PNG also work, but PDF is optimal for text documents.

What resolution should I use?

At least 200 DPI (dots per inch). For very detailed documents or small text, 300 DPI is better. Higher resolutions offer little benefit, as fax machines have a limited resolution.

Are colours transmitted?

No, faxes are transmitted in black and white or greyscale. Colour content is automatically converted to greyscale. Please check in advance that your document is also easy to read in black and white.

Still not resolved?

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