The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Fix side and a seamless pattern formed from circles.
Source SliverKnight
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
A version without colours blended together to give a different look.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
This one needs to be used in small areas; you can see it repeat.
Source Luca
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo