A seamless marble-like texture colored in light blue.
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
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
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
Classic vertical lines, in all its subtlety.
Source Cody L
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ