This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Neat little photography icon pattern.
Source Hossam Elbialy
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
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
Retro Circles Background 4 No Black
Source GDJ
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Prismatic Abstract Background Design No Black
Source GDJ
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
A comeback for you: the popular Escheresque, now in black.
Source Patten
Colourful background achieved with gradient fills.
Source Firkin