A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
A seamless background texture of old cardboard.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
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
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A pattern formed from repeated instances of corner decoration 8. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Continuing the geometric trend, here is one more.
Source Mike Warner
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin