A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Gold Triangular Seamless Pattern No Background
Source GDJ
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Element of beach pattern with background.
Source Rones
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin