The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
This is a remix of "geometrical pattern 01".
Source Yamachem
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
A new one called white wall, not by me this time.
Source Yuji Honzawa
A bit strange this one, but nice at the same time.
Source Diogo Silva
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
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 Abstract Geometric Background 2 No Black
Source GDJ
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
A seamlessly tileable pink background texture.
Source V. Hartikainen
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop