A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
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 pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Same classic 45-degree pattern, dark version.
Source Luke McDonald
Element of beach pattern with background.
Source Rones
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
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
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Abstract Tiled Background Extended 10
Source GDJ
Pattern formed from simple shapes. Black version.
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A seamless stone-like background for blogs or any other type of websites.
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
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen