Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
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 seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
Subtle scratches on a light gray background.
Source Andrey Ovcharov
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
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
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
You may use it as is, or modify it as you like.
Source V. Hartikainen
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin