Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
The image is a seamless pattern which is derived from a vine .Consequently, the vine got like dots via vectorization.The original vine is here:jp.pinterest.com/pin/500744052301410188/
Source Yamachem
Prismatic Polyskelion Pattern No Background
Source GDJ
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background
Source GDJ
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin