The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
A seamlessly tileable pink background texture.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
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
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media