Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
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
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A bit strange this one, but nice at the same time.
Source Diogo Silva