Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
There are many carbon patterns, but this one is tiny.
Source Designova
Original seamless pattern with an Inkscape filter.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
This seamless light brown background texture resembles a wallpaper with vertical stripes. One way to use it is as a tiled background on web sites.
Source V. Hartikainen