Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A background pattern with a look of rough fabric.
Source V. Hartikainen
Retro Circles Background 4 No Black
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Original seamless pattern with an Inkscape filter.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Polyskelion Pattern No Background
Source GDJ
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Abstract Ellipses Background Grayscale
Source GDJ
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton