This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
It’s big, it’s gradient—and it’s square.
Source Brankic1979
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen