A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
An alternative colour scheme for the original seamless texture formed from an image on Pixabay.
Source Firkin
Derived from a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin