This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Might not be super subtle, but quite original in its form.
Source Alex Smith
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Prismatic Abstract Geometric Background 3
Source GDJ
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Green Background Pattern
Source V. Hartikainen
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
A dark metal plate with an embossed grid pattern and a bit of rust. Here's a dark metal plate texture for use as a tiled background on web pages.
Source V. Hartikainen
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin