Portuguese tiles are a cultural heritage and a continued tradition.
They are used to waterproff walls giving more durability to constructions but the main importance is taht they were, and are, works of art outside and inside the houses, churches, palaces and even as street art.
Instead of Fresco (like in Intaly) we have azulejo (tile) and we are lucky because they are still in his place and don't need so much interventions.
Aldo they are more easy to steal and have been seatled and sold.
Artisans still do handpainted tiles. Some factories too. Factories also continue to make stenciled tiles and creating new patterns.
Find more about portugese tiles history:
http://www.golisbon.com/culture/azulejos.html
http://www.portugaldailyview.com/05-culture/the-national-tile-museum-rediscovers-a-piece-of-history
Recently I began painting tiles. Using the antique technique I recreate old patterns and figures.
First I use a photo from old tiles in place and trace them with transparent paper.
The paper is them perforated along the lines with a pin.
Laying the paper carefully over the raw tile I cover the paper with charcoal powder making doted lines apear on the surface.
The inks are metal oxides powder mixed into water. They are not soluble so his density deppends on being allways mixed every time we use the brush.
teh brush strokes are instantly aborved by the surface, so is the colour whar makes tile painting almost impossible to erase or paint over to change a mistake. It also makes the brush strokes visible even after turned into glaze.
The tiles needs to be burned (second time) in a kiln to turn the metal oxides in a glass like cover.
They are resistant to time, weather, rain, cold, warm, etc. They just need to be transported carefully befor being applied on a wall or frame.
Find some of my works at my etsy store https://www.etsy.com/pt/shop/Atocks?section_id=18324893&ref=shopsection_leftnav_6