Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
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
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
Colour version of the original seamless pattern.
Source Firkin
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Continuing the geometric trend, here is one more.
Source Mike Warner
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson