Looks like an old rug or a computer chip.
Source Patutin Sergey
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
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 seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Have you wondered about how it feels to be buried alive? Here is the pattern for it.
Source Hendrik Lammers
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
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.
Source Firkin