People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Remixed from a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin