A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
"Beige Stone", Tileable Texture.
Source V. Hartikainen
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
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
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Number five from the same submitter, makes my job easy.
Source Dima Shiper
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Subtle scratches on a light gray background.
Source Andrey Ovcharov
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
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes