The tile can be had by selecting the rectangle in Inkscape and using shift+alt+i. Remixed from a drawing in 'Flowers of Song', Frederick Weatherly, 1895.
Source Firkin
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Seamless Olive Green Web Background Image
Source V. Hartikainen
Sharp pixel pattern, just like the good old days.
Source Paridhi
Geometric triangles seem to be quite hot these days.
Source Pixeden
Just like the black maze, only in light gray. Duh.
Source Peax
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Sort of reminds me of those old house wallpapers.
Source Tish
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I have no idea how to describe this one, but it’s light and delicate.
Source JBasoo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers