Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Prismatic Hypnotic Pattern No Background
Source GDJ
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica