This is so subtle you need to bring your magnifier!
Source Carlos Valdez
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Prismatic Snowflakes Pattern No Background
Source GDJ
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
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 is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
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
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Prismatic Chevrons Pattern 5 With Background
Source GDJ