Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A blue gray fabric-like texture for websites. An yet another fabric-like texture. It has subtle vertical and diagonal stripes to it.
Source V. Hartikainen
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
A free seamless background with pink spots.
Source V. Hartikainen
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
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 formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
A new one called white wall, not by me this time.
Source Yuji Honzawa
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees