This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
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
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A white version of the very popular linen pattern.
Source Ant Ekşiler
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin