Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
This is a hot one. Small, sharp and unique.
Source GraphicsWall
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett