Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
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
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Basic Pattern 2 No Background
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
Spice up your next school project with this icon background.
Source Swetha
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo