Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
The name is totally random, but hey, it sounds good.
Source Atle Mo
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.
Source Yamachem
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin