Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
This is a hot one. Small, sharp and unique.
Source GraphicsWall
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
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
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Prismatic Groovy Concentric Background
Source GDJ