The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Classic vertical lines, in all its subtlety.
Source Cody L
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
ZeroCC tileable mossy (lichen) stone texture, edited from pixabay. CC0
Source Sojan Janso
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Prismatic Floral Background No Black
Source GDJ
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos