A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Prismatic Groovy Concentric Background No Black
Source GDJ
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
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
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Abstract Tiled Background Extended 10
Source GDJ
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin