A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Remixed from a drawing in 'Kulturgeschichte der Deutschen im Mittelalter' Franz von Loeher, 1891. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Subtle scratches on a light gray background.
Source Andrey Ovcharov
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Prismatic Abstract Background Design
Source GDJ
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen