Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A yellow tiled background... Blurriness, bokeh effect and rectangles pattern in one mix.
Source V. Hartikainen
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
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
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
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers