A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin