I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Abstract Tiled Background Extended 8
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
This seamless light brown background texture resembles a wallpaper with vertical stripes. One way to use it is as a tiled background on web sites.
Source V. Hartikainen
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Prismatic Geometric Pattern Background No Black
Source GDJ
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić