From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 4
Source GDJ
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Seamless pattern made from a tile that can be obtained in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
8 by 8 pixels, and just what the title says.
Source pixilated
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
You know you love wood patterns, so here’s one more.
Source Richard Tabor
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Looks as if it's spray painted on the wall. You can be sure that this pattern will seamlessly fill your backgrounds on web pages.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo