The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
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
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
The original enhanced with one of Inkscapes's filters.
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Background Design No Black
Source GDJ