A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Prismatic Geometric Pattern Background 2
Source GDJ
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Prismatic 3D Isometric Tessellation Pattern 6
Source GDJ
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless texture of an abstract wall colored in shades of light orange brown.
Source V. Hartikainen
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
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen