Prismatic Groovy Concentric Background
Source GDJ
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Textured Red Brown Plastic, Free Background Pattern. Although there's already enough plastic in our lives, let's bring it to the web too.)
Source V. Hartikainen
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Tiny circle waves, almost like the ocean.
Source Sagive
There are many carbon patterns, but this one is tiny.
Source Designova
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
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
A seamlessly tileable pink background texture.
Source V. Hartikainen
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
The image is the remix of "wire-mesh fence seamless pattern" .This is a more minute version of it.Sorry for the file size.Using path>difference in Inkscape, I will cut out any silhouette from this pattern and create a "meshed silhouette".
Source Yamachem
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen