A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Classic 45-degree pattern, light version.
Source Luke McDonald
The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
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
Green Web Background, Seamless tile.
Source V. Hartikainen
Alternative colour scheme for the original floral pattern.
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo