Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Prismatic Triangular Background Design Mark II 5
Source GDJ
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Retro Circles Background 5 No Black
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Seamless Green Tile Background
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A version without colours blended together to give a different look.
Source Firkin
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH