A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
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
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas