A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Prismatic Abstract Background Design
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
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A seamless pattern formed from background pattern 102
Source Firkin
A free pink background pattern.
Source V. Hartikainen
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton