CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
Just like the black maze, only in light gray. Duh.
Source Peax
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
There are many carbon patterns, but this one is tiny.
Source Designova
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
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 background pattern with a look of rough fabric.
Source V. Hartikainen
Prismatic Abstract Background Design
Source GDJ
A seamless canvas texture for using as background on websites. Colored in pale tones of brown.
Source V. Hartikainen
A new take on the black linen pattern. Softer this time.
Source Atle Mo
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Prismatic Hexagonalism Pattern No Background
Source GDJ
Prismatic Abstract Geometric Background 4
Source GDJ
Same classic 45-degree pattern, dark version.
Source Luke McDonald
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin