Number five from the same submitter, makes my job easy.
Source Dima Shiper
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
It looks very nice I think.
Source V. Hartikainen
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts