You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Prismatic Groovy Concentric Background No Black
Source GDJ
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Prismatic Abstract Line Art Pattern Background
Source GDJ
The original has been presented as black on transparent and stored in the pattern definitions. To retrieve the unit tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This could be a hippy vintage wallpaper.
Source Tileable Patterns
A yellow tiled background... Blurriness, bokeh effect and rectangles pattern in one mix.
Source V. Hartikainen
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
A free background pattern with abstract green tiles.
Source V. Hartikainen
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Abstract Geometric Background 2
Source GDJ