Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
A free pink background pattern.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
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
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Almost like little fish shells, or dragon skin.
Source Graphiste