It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
A seamlessly tile-able grunge background image.
Source V. Hartikainen
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
Derived from an image that was uploaded to Pixabay by TheDigitalArtist
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin