From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is the remix of "Colorful Floral Pattern Background 3" uploaded by "GDJ". Thanks.
Source Yamachem
Prismatic Groovy Concentric Background
Source GDJ
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Prismatic Polka Dots 3 No Background
Source GDJ
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
The image depicts a seamless pattern of a snow crystal.I referred to a book called ”sekka-zusetsu” or "雪華図説" which means an illustrated explanation about snow crystals.This book was published in 1832 (天保3年) or Edo period.For more about "雪華図説",see here:dl.ndl.go.jp/info:ndljp/pid/2536975
Source Yamachem
A floral background formed from numerous clones of flower 117.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen