Not so subtle. These tileable wood patterns are very useful.
Source Elemis
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Remixed from an image that was uploaded to Pixabay by CatherineClennan
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Original minus the background
Source Firkin
Mostly just mucked about with the colours and made one of the paths in the lead frame opaque. The glass remains transparent.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Prismatic Curved Diamond Pattern No Background
Source GDJ
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin