Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
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
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
From a drawing in 'Hyde Park from Domesday-Book to date', John Ashton, 1896.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo