Prismatic Groovy Concentric Background No Black
Source GDJ
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Alternative colour scheme for the original floral pattern.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
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
Abstract Tiled Background Extended 11
Source GDJ
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz