Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a drawing in 'Az Osztrák-Magyar Monarchia irásban és képben', 1885.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Might not be super subtle, but quite original in its form.
Source Alex Smith
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
With a name like this, it has to be hot. Diagonal lines in light shades.
Source Isaac
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
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
Alternative colour scheme for the original floral pattern.
Source Firkin
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
White circles connecting on a light gray background.
Source Mark Collins
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
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
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin