This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image is a design of blue glass.How about using it as background image?
Source Yamachem
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
I’m not going to use the word Retina for all the new patterns, but it just felt right for this one. Huge wood pattern for ya’ll.
Source Atle Mo
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Alternative colour scheme to the original.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin