This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
Embossed lines and squares with subtle highlights.
Source Alex Parker
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A pale olive green background with a seamless texture.
Source V. Hartikainen
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
Prismatic Hexagonalist Pattern No Background
Source GDJ
White circles connecting on a light gray background.
Source Mark Collins
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees