Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A pattern formed from repeated instances of corner decoration 8. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Prismatic Abstract Geometric Background 5
Source GDJ
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
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
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso