Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
Psychedelic Geometric Background No Black
Source GDJ
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Remixed from a PNG that was uploaded to Pixabay by gingertea
Source Firkin
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Prismatic Polka Dots 3 No Background
Source GDJ
White circles connecting on a light gray background.
Source Mark Collins
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Seamless Prismatic Geometric Pattern With Background
Source GDJ
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin