Green Web Background, Seamless tile.
Source V. Hartikainen
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 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Prismatic Abstract Background Design No Black
Source GDJ
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Retro Circles Background 5 No Black
Source GDJ
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Classic vertical lines, in all its subtlety.
Source Cody L
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin