I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
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
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Spice up your next school project with this icon background.
Source Swetha
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
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