To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Prismatic Abstract Background Design No Black
Source GDJ
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin