Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Someone was asking about how to achieve a fur pattern at #inkscape irc so tried to make a filter on it. Flood filled fractal noises rigged together. May someone find a good use for these.
Source Lazur URH
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Sort of reminds me of those old house wallpapers.
Source Tish
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen