This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
By popular request, an outline version of the pentagon pattern.
Source Atle Mo
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Gold Triangular Seamless Pattern No Background
Source GDJ
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen