Looks like an old rug or a computer chip.
Source Patutin Sergey
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
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
A seamless web background with texture of aged grid paper.
Source V. Hartikainen
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Retro Circles Background 4 No Black
Source GDJ
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
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
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
This is the remix of "polka dot seamless pattern".The image depicts polka dot seamless pattern.
Source Yamachem
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin