Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
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
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
A pale olive green background with a seamless texture.
Source V. Hartikainen
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ