A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Dead simple but beautiful horizontal line pattern.
Source Fabian Schultz
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Tiny circle waves, almost like the ocean.
Source Sagive
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
A repeating background with wood/straw like texture.
Source V. Hartikainen
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin