Not so subtle. These tileable wood patterns are very useful.
Source Elemis
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Background formed from the original with an emboss effect.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Prismatic Abstract Geometric Background 2
Source GDJ
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Classic 45-degree pattern, light version.
Source Luke McDonald
Prismatic Snowflakes Pattern No Background
Source GDJ
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Subtle scratches on a light gray background.
Source Andrey Ovcharov
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen