You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Just the symbols of the signs of the zodiac distributed in a chequer board-like pattern
Source Firkin