Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
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
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin