From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
CC0 and seamless wellington boot pattern.
Source SliverKnight
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Background formed from the original with an emboss effect.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso