This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba