From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Prismatic Geometric Pattern Background No Black
Source GDJ
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Seamless Olive Green Web Background Image
Source V. Hartikainen
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin