A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
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
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This one is amazing, truly original. Go use it!
Source Viahorizon
Prismatic Groovy Concentric Background No Black
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Looks like an old rug or a computer chip.
Source Patutin Sergey
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
A repeating background of beige paper with vintage look. Repeats to infinity, as usual.
Source V. Hartikainen
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten