Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
The classic notebook paper with horizontal stripes.
Source Are Sundnes
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin