By popular request, an outline version of the pentagon pattern.
Source Atle Mo
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
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
It’s big, it’s gradient—and it’s square.
Source Brankic1979
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Prismatic Groovy Concentric Background 2
Source GDJ
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ