An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Seamless Green Tile Background
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
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
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green