Not so subtle. These tileable wood patterns are very useful.
Source Elemis
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ