Nothing like a clean set of bed sheets, huh?
Source Badhon Ebrahim
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Non-seamless pattern drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Background pattern originally a PNG drawn in Paint.net
Source Firkin