Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
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
U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.
Source Firkin
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
A new one called white wall, not by me this time.
Source Yuji Honzawa
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Prismatic Geometric Tessellation Pattern 2 No Background
Source GDJ
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Green Background Pattern
Source V. Hartikainen
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin