Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A repeating background of beige (or is it more vanilla yellow) textured stripes. One more background with stripes.
Source V. Hartikainen
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Prismatic Abstract Geometric Background 2
Source GDJ
This one is amazing, truly original. Go use it!
Source Viahorizon
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
Prismatic Polyskelion Pattern No Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz