Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Might not be super subtle, but quite original in its form.
Source Alex Smith
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
White circles connecting on a light gray background.
Source Mark Collins
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus