A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Formed by distorting an image on Pixabay that was uploaded by gustavorezende. To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A dark metal plate with an embossed grid pattern and a bit of rust. Here's a dark metal plate texture for use as a tiled background on web pages.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ