Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
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
Classic vertical lines, in all its subtlety.
Source Cody L
A version without colours blended together to give a different look.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Looks like an old rug or a computer chip.
Source Patutin Sergey
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
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
Prismatic Groovy Concentric Background 5
Source GDJ
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin