Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
Prismatic Snowflakes Pattern No Background
Source GDJ
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen