A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
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
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
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
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
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
The image is a seamless pattern of a fishnet.
Source Yamachem
A seamlessly tile-able grunge background image.
Source V. Hartikainen