There are many carbon patterns, but this one is tiny.
Source Designova
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Prismatic Groovy Concentric Background No Black
Source GDJ
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien