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
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Prismatic Geometric Pattern Background 2
Source GDJ
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
The classic notebook paper with horizontal stripes.
Source Are Sundnes