This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
This one needs to be used in small areas; you can see it repeat.
Source Luca
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
A floral background formed from numerous clones of flower 117.
Source Firkin
A pale olive green background with a seamless texture.
Source V. Hartikainen
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
No idea what Nistri means, but it’s a crisp little pattern nonetheless.
Source Markus Reiter
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
Prismatic Geometric Pattern Background 2 No Black
Source GDJ