It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Prismatic Geometric Pattern Background
Source GDJ
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
Remixed 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
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
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
A version without colours blended together to give a different look.
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen