A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
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
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Kaleidoscope Prismatic Abstract No Background
Source GDJ
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen