Sort of reminds me of those old house wallpapers.
Source Tish
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
One more sharp little tile for you. Subtle circles this time.
Source Blunia
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
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A seamless texture of worn out "cardboard".
Source V. Hartikainen
A seamless texture of a rough concrete surface.
Source V. Hartikainen
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
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
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ