From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Seamless pattern inspired by a drawing on Pixabay. To get the tile this is formed from, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
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
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
Lovely pattern with splattered vintage speckles.
Source David Pomfret
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin