Looks like an old rug or a computer chip.
Source Patutin Sergey
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
This one is amazing, truly original. Go use it!
Source Viahorizon
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin