Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
The image is a seamless pattern of a fishnet.
Source Yamachem
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Remixed from an image on Pixabay uploaded by Prawny
Source Firkin
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Prismatic Groovy Concentric Background 2 No Black
Source GDJ