Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
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 name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
Colorful Floral Background No Black
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Number five from the same submitter, makes my job easy.
Source Dima Shiper
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen