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
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
This one is amazing, truly original. Go use it!
Source Viahorizon
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Geometric triangles seem to be quite hot these days.
Source Pixeden
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Psychedelic Geometric Background No Black
Source GDJ
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko