The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Prismatic Triangular Background Design Mark II 5
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
Green Web Background, Seamless tile.
Source V. Hartikainen
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
From an image on opengameart.org shared by rubberduck.
Source Firkin
Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
It looks very nice I think.
Source V. Hartikainen
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
Prismatic Floral Background No Black
Source GDJ
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Prismatic Abstract Geometric Background 2
Source GDJ
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo