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
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
This is sort of fresh, but still feels a bit old school.
Source Martuchox
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Just the symbols of the signs of the zodiac distributed in a chequer board-like pattern
Source Firkin
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin