This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Background pattern originally a PNG drawn in Paint.net
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
This is a remix of "geometrical pattern 01".
Source Yamachem
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
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
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A bit strange this one, but nice at the same time.
Source Diogo Silva
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
You guessed it – looks a bit like cloth.
Source Peax Webdesign
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Spice up your next school project with this icon background.
Source Swetha
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin