A seamless background of warped stripes on paper.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
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
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Neat little photography icon pattern.
Source Hossam Elbialy
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A frame using leaves from an image that was uploaded to Pixabay by mayapujiati
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin