From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Prismatic Basic Pattern 2 No Background
Source GDJ
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
A seamlessly tile-able grunge background image.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin