To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.
Source V. Hartikainen
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Gold Triangular Seamless Pattern No Background
Source GDJ
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
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
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
A seamless pattern formed from background pattern 102
Source Firkin