A comeback for you: the popular Escheresque, now in black.
Source Patten
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Light and tiny, just the way you like it.
Source Rohit Arun Rao
A nice and simple white rotated tile pattern.
Source Another One
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin