Could be paper, could be a Polaroid frame – up to you!
Source Chaos
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
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
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Prismatic Abstract Background Design No Black
Source GDJ
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
A set of paper filters. The base texture is generated the same way, only the compositing mode is varied.
Source Lazur URH
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen