Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
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
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
A seamless paper background colored in pale yellow.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
Colorful Floral Background No Black
Source GDJ
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
From a drawing in 'Az Osztrák-Magyar Monarchia irásban és képben', 1885.
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
One more sharp little tile for you. Subtle circles this time.
Source Blunia
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem