The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
This is a more minute version of "fishnet 01".The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
You may use it as is, or modify it as you like.
Source V. Hartikainen
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Prismatic Hexagonalism Pattern No Background
Source GDJ
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Prismatic Groovy Concentric Background 2
Source GDJ
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Prismatic Groovy Concentric Background No Black
Source GDJ
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Retro Circles Background 8 No Black
Source GDJ