Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
A bit strange this one, but nice at the same time.
Source Diogo Silva
Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.
Source Firkin
Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.
Source JayNick
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
White handmade paper pattern with small bumps.
Source Marquis
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin