The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
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
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
You guessed it – looks a bit like cloth.
Source Peax Webdesign
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
A seamless paper background colored in pale yellow.
Source V. Hartikainen
Light and tiny, just the way you like it.
Source Rohit Arun Rao
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Prismatic Triangular Background Design Mark II 5
Source GDJ
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
A textured orange background pattern with vertical stripes.
Source V. Hartikainen
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
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