This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Geometric triangles seem to be quite hot these days.
Source Pixeden
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
A version without colours blended together to give a different look.
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
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
Prismatic Polka Dots Mark II No Background
Source GDJ
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
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
This is a remix of "geometrical pattern 01".
Source Yamachem
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle