There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Prismatic Groovy Concentric Background No Black
Source GDJ
Retro Circles Background 7 No Black
Source GDJ
Looks like an old rug or a computer chip.
Source Patutin Sergey
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian