A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
A pale olive green background with a seamless texture.
Source V. Hartikainen
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Prismatic Polyskelion Pattern No Background
Source GDJ