Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Sharp pixel pattern, just like the good old days.
Source Paridhi
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Prismatic Polka Dots Mark II No Background
Source GDJ
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Retro Circles Background 4 No Black
Source GDJ
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
Number five from the same submitter, makes my job easy.
Source Dima Shiper