Ceramics 101: Underglaze Techniques

Hello! In this video I'm going to be showing you a bunch of different techniques for underglazing. The first is Sgraffito. So I have a slab here and a variety of amical underglazes. We're just going to stir the underglaze, make sure it's all consistent throughout, and I'm just going to paint a layer of black underglaze on this slab. My slab is still quite soft at this point, I've just rolled it. You could do about two coats of underglaze here and let it stiffen up. You don't want it completely dry, you want to keep it at least leather hard, so just so the underglaze is firm to the touch. Once it's ready you can take any sort of incising tool and start carving into the clay. The main thing is you want to clean off your tool frequently so that you don't get underglaze inside of your incised lines. And the key thing to Sgraffito is making sure that your carving is clean. So we don't want any crumbs in there, we don't want underglaze underneath it. And you can create all kinds of different designs using this technique. The next one is a layered Sgraffito, so I'm going to actually create a rainbow effect with this one. It's important you want to put at least two coats of each color over this and let it stiffen up in between each coat. And once you're done you can take a wire loop tool or any other sort of carving tool and carve through it. And that's going to give you this sort of like heat transfer image or I guess whatever color you choose to use is going to create this rainbow effect as you carve into it. Varying the pressure of your carving is going to give you different effects as well. And the key thing is the drier your clay is the harder it's going to be to carve into this. So my clay is still leather hard and it's actually really easy to carve into, but if you wait until your clay is closer to bone dry it's going to be really difficult. And you can use just a variety of different tools to carve into things to create different textures as you're working. The third technique I'm going to show you is a newsprint transfer. So I'm going to paint a design on a piece of newsprint and whatever you put on first is what's going to be on top of your image. So keep that in mind. Also keep in mind everything's going to be backwards. So if you're painting words or letters you need to do it backwards. Once it's dry I can create another layer and I can keep layering this as much as I want, but I'm just going to do two layers here. So just a light layer of this other color. And once you're ready you can flip it over whether it's wet or dry. So I'll flip mine over here and I'm going to lay it down. The clay is still a little leather hard so that'll help to make it stick. But then you can take a sponge or a water bottle and kind of spray over it too. Then use a rib to smooth the newsprint on as good as you can. I'm going to take a damp sponge over this to help the transfer just a little bit further. Just kind of going back and forth between the sponge and the rib. And once I'm ready I can peel it off and voila you have a transfer. The next technique is an inlay also known as mashima. So what I've done is I've carved into my clay and my clay is now close to bone dry at this point makes it a little bit easier. The key thing is you want to make sure your clay is very or your carving is very clean and doesn't have any crumbs or raised edges. That will make this a lot easier and cleaner looking when you're finished. So I'm filling the cracks with underglaze at this point. If I were doing true mashima I would actually just lay a really thick layer of colored slip into this until it's level with the top of the clay. Once it's dried I'm going to take a sponge and just wipe off that excess underglaze here. You can do this on bisquare as well as bone dry clay. It does work on softer clay but it gets a little messier so I like to wait until it's a little drier or until it is fired to do this stage. So I'm just going to gently wipe my sponge across this. If I had done the true mashima and layered a large layer of slip over the top of this I'd have to kind of grind it down and sand it down before I got to this point and then the true inlay would be level with the clay like it's a part of it. This one there's still a little bit of an indent going on but this is a great way to get different colors into your clay to make words and other designs stand out. Next we have regular painting. Nothing special about this we're just using our underglaze to paint with and just treat it exactly the same way you'd use other paints. You can mix them together on a palette and create custom colors. You can blend them together. If you're working on bone dry clay like I am here it dries really quickly so you have to work kind of fast to get them to blend together and kind of keep going back and forth over the top of one another. And I can create all kinds of layers and designs and anything from like large blended areas to intricate designs with my underglaze at this point. The key thing to remember is that once you fire this the colors are going to be a lot more saturated as we go along. So let's throw this into the kiln and we're gonna bisque fire it. Now there's nothing better than opening a nice warm kiln on a cold winter day. So here we have our bisque square tile. As you can see the colors are a lot more saturated at this point and I'm just going to layer everything with three coats of clear glaze. The glaze is going to make it even more saturated and also if this were say a cup or something it would make it waterproof and not porous anymore. So three coats of glaze and at this point while we're waiting for that to dry we're going to show our last style and that's miolica. So what I'm going to do in this bottom corner is lay three coats of white glaze down and miolica is a sort of a traditional technique where most people would use like tin based glazes over the top of this but you can use underglaze as well. So you can treat this almost like watercolor over the top of the glaze and paint your designs on top of it. So I'm just going to do like a quick little doodle over the top of this and the underglaze kind of sinks into the glaze as it fires. As long as you don't put a ton of underglaze over the top of it still maintains that sort of shiny texture to it. If you put a little too much on it then it's going to have a different sort of texture and consistency once it's fired. So it's important to kind of keep it thin when you're working in the miolica technique. And we're going to pop this into the glazeware kiln and we'll see our finished results in 24 hours. All right I've taken everything out of the kiln and now we can see everything all finished up. So we've already seen the inlay and the transference graffito but here's miolica. We can see how the underglaze kind of sunk under and everything gets a little more vibrant after it's been glaze fired. So here's a whole bunch of different kinds of underglaze techniques that you can use when you're working with clay. Thanks for watching!