It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
A seamless web background with texture of aged grid paper.
Source V. Hartikainen
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
An aged paper background tile with smeared and pressed text.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Plywood Web Background background image for use in web design.
Source V. Hartikainen
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ