This one needs to be used in small areas; you can see it repeat.
Source Luca
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
The image depicts a pattern of regular hexagon.As I made to use it for myself,I want to others to use it.Speaking about the ratio of the image, height : width = 2 : √3(1.732...)Ridiculous to say,I realized later that this image is not honey comb pattern.I have to slide the second row.
Source Yamachem
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
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
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin