This could be a hippy vintage wallpaper.
Source Tileable Patterns
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
A comeback for you: the popular Escheresque, now in black.
Source Patten
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Prismatic Abstract Line Art Pattern Background 2
Source GDJ