Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
It’s big, it’s gradient—and it’s square.
Source Brankic1979
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Prismatic Groovy Concentric Background 2
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
From an image on opengameart.org shared by rubberduck.
Source Firkin
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin