Monday, July 19, 2010

More bookmarks and pendant settings

I received more cabachon settings, including some in silver, so I thought I would share them. This silver filligree one was among my favorites. I made a handful of them, thinking that I would link them together (see the corner connectors) to make a Victorian styled cuff bracelet. Unfortunately I didn't have any beads in colors to match the glaze that I used. (I wasn't able to get the color in the photo right, either. It's actually a lot more lavender than rose in tone.)

The order also contained more bookmark blanks, including silver. I suspect another color of glaze would compliment the silver better, but I had done a large batch of this shade of green so it was what I had. (It's my favorite for testing things because it is a very predictable glaze, which is a rarity in the colored glazes.)

Here are two more of the pendant setting styles in antique brass. There are other styles, and most came in silver, too. I ran out of beads before I ran out of settings. They are also different glazes, though I suppose dark and light turquoise aren't that far from green. I need to pull out some of the red and blue glazes when I get back from Kentucky.

Speaking of which, while I won't be selling at the Artisan's Gallery this year, I will bring samples of these and some of the other jewelry components for anyone who would like to see them in person. I find art glazed pieces harder to accurately photograph, especially at this level of magnification. (The filligree piece, which is the largest of them, is only 1.25" across.)

Saturday, July 17, 2010

Breakables Challenge Awards

I leave in just a few days for the North American Nationals and BreyerFest. I haven't attended the event in the last few years, so I am really looking forward to seeing old friends. I also plan to take lots of pictures so I can share them here. For those readers that aren't involved in the equine collectibles community (as I've recently learned many here are not), BreyerFest is an annual event sponsored by Reeves International for collectors of their Breyer model horses. Almost as soon as it began, it became the defacto national gathering place for those interested in three-dimensional equine collectibles of all kinds.

The North American Nationals (usually just called "NAN") is the national competition for the model horse industry. NAN rotates coasts every other year, so that on even-numbered years it is held in conjunction with BreyerFest. BreyerFest draws a large number of people from all over the world to Lexington each year, and for those years that it is paired with the Nationals it is larger still.

This year the event has another draw for those of us involved in the ceramic end of the industy. Maggie Barkovitz has brought back the all-ceramic show "Breakables".

I am bringing along some green art glazed "Inspire" tiles for the winners of the Breakables Blackberry Lane Challenge class. I'm hoping to include some matching bookmarks, too, if my order for the brass blanks gets here in time.

Handling backgrounds

These two Inspire tiles show the two different approaches to handling backgrounds: painting the horse first, and painting the background first.

The first approach is perhaps the easiest, since it involves finishing the horse in exactly the same way ceramic horses are done. The tile in the picture just has the base coloring applied. He'll eventually be a darkly dappled buckskin, so the tile will go through several more layers (and firings) before the clear glaze is applied. With each step, the background will be masked during spraying and then removed for firing. After all the detailing is done, clear glaze will be applied to the horse and fired. At that point there is a completely finished, glossy horse on a bare bisque background.

At that point, the art glaze can be applied to the background using an ordinary paint brush. Since the horse has a hard gloss finish, it is easy to clean any excess art glaze from the horse. That's really the only trick to this approach. The art glaze must not overlap the clear glaze or it will bleed onto the horse during firing. It's also a good idea not to apply it too thick close up against the edge of the horse.

The second approach is to paint the background first in Concepts. Because this type of underglaze is hard and semi-glossy after bisque firing, it can be masked over. Ordinary underglazes are so fragile, even after they are fired, that removing latex from them causes scuffing and chipping. They are also porous, so the latex bonds strongly and is often very difficult to remove. Concepts and the other brands do vary, but every one that I have used does hold up well enough to masking. Some colors fire glossy enough that it's even possible to remove overspray without masking, because it wipes off with a damp sponge.

With background-first tiles, the clear glaze is not added until the entire tile is done. When it is applied, it is added to the entire tile. The areas covered by Concepts don't usually require a lot of glaze, but they do need some to be truly sealed.

It is also possible to combine all three approaches. The Celtic Pony in the blog header was done this way. His bridle was done with airbrushed Concepts, which were then bisque fired. After that, he was painting just as any other realistically colored horse. Because the Concepts used were quite glossy, and because they were very dark (light colors sink below darker ones in underglaze), I didn't bother to mask it. I just airbrushed the colors of the face and then wiped away anything on the bridle. After that was bisque fired, I added clear glaze to the entire pony and ran it through a glaze firing. Then the green art glaze was added to the background and the medallion was sent through its second and final glaze firing.

Both systems seem to work equally well, though each does have a drawback. Art glazes are really unpredictable, so it's possible to get a background too dark or too light or just plain unattractive with the color of the horse. Concepts, on the other hand, give a lot more control over the final look, but the finish is extremely fragile until it is fired so handling it without scuffing some off the edges is a pain. For the most part, it really depends on which look you prefer.

Monday, July 12, 2010

Removing underglaze

One thing I worry about when blogging is that after three years, I often forget whether or not I have already posted about something. For every post I make, I usually have two or three that I meant to post, so it's hard to keep track of which ones were written and which ones I only thought about writing! Maybe there is a reason I am so fond of this "flair" from Facebook: maybe I am closer to making those "new friends" than I think!

So with apologies in case I have previously passed this tip along, I wanted to include it before I got back to using Concepts and art glazes. It's a pretty important detail, so it really deserves its own post anyway.

The post from a few days ago showed how Concepts interact with latex masking. It's an important thing because almost all underglazes are airbrushed. It's almost impossible to create an even tone with them any other way because they streak. Raw (that is, unfired) underglaze also looks opaque long before it really is, so the streaking isn't visible until after the piece has gone through it's final gloss fire. At that point, everything is permanent.

Masking is used to protect those areas that need to stay white. Because earthenware bisque is porous, it is almost impossible to completely remove color after it has been applied to the surface. The only drawback is that none of the most common forms of masking - liquid latex, wax, tape and foil - give a very precise line. They are not suited to fine detail. For that reason, the final edges are usually etched with a blade or other sharp tool.

With some underglaze colors, this works really well. Others are more resistant, or leave a more pronounced stain. For that reason, it's often a good idea to apply a barrier between the underglaze and the bisque.

I have found the best choice for this is the Duncan Cover Coat "Arctic White" (CC 101). It fires to about the same color as white earthenware, so it doesn't really effect the final color. It does etch off really easily, though.

There is more information about why lighter colors do not change darker colors in this older post.)

That's why it makes a useful mask for the last few millimeters of a pattern. The larger areas of the pattern (or in the case of my current tiles, the background) are masked with liquid latex, but the area closest to the final border is thin layer of Arctic White. Unlike the rest of the underglaze, I apply it with a small brush. It's also a little more flexible than the latex because I can decide to leave an area (ie., not etch it off) and it will fire normally. Were it latex, traditional underglaze would flake off.

A similar approach is taken with patterns that have a lot of body roaning. For situations like that, the Arctic White is airbrushed in a light coat before the other colors are added. Doing this makes the body color more fragile and prone to scuffing, but with roaned horses that is usually pretty easy to correct or at least camouflage.

Here is the Inspire tile from the previous post (the one with the bright green background). I painted the inside edge of the horse with Arctic White, then applied the liquid latex. The second tile, which isn't pictured yet, will have the horse painted first so the outside edge was painted white and the mask was applied to the background.

I'll explain the two different approaches ("background first" and "horse first") in the next post.

Saturday, July 10, 2010

This is just too cool

I will post again about underglazes and art glazes, but I just had to share this. I thought it was neat that there were pendant settings for the smallest of my beads, but finding out they fit these antique brass bookmarks was just too cool!

Friday, July 9, 2010

Underglazing with Concepts

As I mentioned in the previous post, the newer types of underglazes (Concepts, Stroke & Coats, SuperStrokes) are often problematic for painting realistic horses. They are popular at what are known in the ceramic trade as "Contemporary Pottery Studios" (also sometimes called Ceramic Cafes) where people can come and paint bisqueware. That's because they are designed to have the clear glaze applied while still raw, so that the piece is completed in one glaze firing. Traditional underglazes are bisque fired first, and then covered with clear glaze and fired again.

For the sake of simplicity, I'll use the brand name Concepts in this post to refer generally to this type of glaze.

Concepts can be bisque fired like normal underglazes, but they have some properties that make working with them a little different. The most important of these is how they interact with liquid latex. Latex masking fluid is commonly used on ceramic horses to mask off white markings and patterns. I've painted on the bisque tile above in a giant "N" for the world "no" because latex and these kinds of underglaze do not mix.

These two tests have been sprayed with a mixture of Concepts colors. With the "Inspire" tile, I've added directional shading in (traditional) transparent underglaze colors and then completely cleaned the latex from the edges. On the "N" tile, I only sprayed the Concept mixture. Afterwards, I pulled most of the latex off from the letter, but left it on the border. I'll fire them both at Cone 04.

(I should mention that traditional underglaze and Concepts can be intermixed just fine, but the resulting underglaze almost always behaves like a Concept underglaze.)

Here is what happens after the tile is fired. With ordinary underglazes, latex usually burns away or at most leaves flakes of color that can be brushed off easily. With Concepts, the latex melds with the underglaze to form heavy, raised edges of dense color. These will not come off. The only way to remove them is to break away the underlying bisque.

Although it is hard to see in these photos, the rest of the surface is semi-glossy. That makes it hard to add details with transparent underglaze because it will bead along the surface. It also has a slightly pebbled texture that, while it usually fires away once the true glaze is added and fired, makes added detail even more difficult.

That pebbled texture is the other reason that Concepts aren't well suited to body color on horses. The texture goes away with firing, but in many cases it has enough dimension when raw to catch the directional spray. This close-up of the green background on the "Inspire" tile shows this really well. As the darker green was sprayed to catch the edges of the text and border, it also caught the undersides of the "pebbles".

Most of the time these do even out during the final glaze firing. All underglazes tend to diffuse and blend a bit during firing, so the speckled effect usually disappears or is at least toned down. It doesn't always, though. That's not a big deal with a background, where it can look like an artsy treatment, but it can ruin an otherwise nicely-done horse.

The other aspect of the Concepts is that after bisque firing, the finish is as hard as nails. That is a problem if more etching or erasing is needed. But it's the one trait that makes them really useful for medallions. In the next few posts I'll show in more detail the two different approaches to coloring backgrounds.

Thursday, July 8, 2010

Mixing underglazes and art glazes

A question from another ceramic artist had me thinking about the different kinds of glazes used in making decorative pieces like medallions, pendants and beads.

For realistic colored horses, the process used here at the studio is pretty straightforward. The horses are airbrushed with a combination of both opaque and transparent underglazes. Details are added using a combination of erasing, etching and handpainting with transparent underglazes. Afterwards the horse is fired with a clear (usually gloss) glaze.

Giftware that isn't realistically colored, like the medallions that are often used for awards at shows catering to ceramic horses, are done in what are known as "art glazes". Art glazes are designed to "break" over the high spots of a design, so the color is paler there, and then pool in the recesses.

This Christmas ornament I did for my (non-horsey) family and friends a few years ago shows the "breaking and pooling" effect really well. The tiny pendants from the previous post were also done with art glazes. (The one that was done in green and blues used a blue glaze which was wiped off the high spots and then painted over with a pale green glaze so that the high spots would be green instead of pale blue.)

There is also a third kind of colorant that falls somewhere between a true underglaze and an art glaze. It gives a flat, opaque color like an underglaze, but unlike traditional underglazes it bisque fires with a hard, often semi-glossy finish. True underglazes are extremely matte, almost chalky, after firing. Often these kinds of underglaze - which are marketed under the names Stroke & Coat (Mayco) and Concepts (Duncan) - are easier to find than traditional underglazes, which is unfortunate for anyone wanting to do the kind of underglazing used for ceramic horses because they don't behave quite the same way.

They are, however, extremely useful in combination with traditional underglazes when backgrounds are involved. The dapple grey Arabian pendant above (the original 1.5" version of the piece that was shrunk in the previous post) had a background done with Concepts.

The tiny bit of blue background under the horse's jaw on this medallion was also done with Concepts.

The bay Celtic Pony at the beginning of this post, and the pinto one that decorates the blog header, were done with traditional underglaze (the ponies), art glazes (on the backgrounds) and Concepts (the bridles).

Over the next few days I will to explain when and why I use art glazes and Concept-type underglazes, and why something other than traditional underglaze is needed for this kind of project. I will also show how I get underglazed finishes to "play nice" with art glazes - or at least how I tilt the odds in my favor that they will play nice!

Monday, July 5, 2010

Ceramic beads and base metals

This July marks my third year of blogging from the studio. I used the above image in the first post I made. I suppose it's appropriate, then, to return to the design now.

My original intention, when I sculpted the pendant, was to have a three-dimensional "test tile" for underglazing techniques. Because airbrushing underglazes involves a lot of directional shading, having something horse-shaped really is important when you are first learning. (That was actually the purpose behind the "Inspire" tiles, but more on that in a future post.)

The little pendant got some use for testing underglazes, but I quickly got brave enough that most of the testing went on to full-bodied models. It did prove really valuable for testing art glazes, though. Low-fire art glazes like the ones commonly used for award medallions are designed so that darker pigment pools in the recesses. This is great for textured surfaces, and is one reason why a lot of the backgrounds on my medallions have stamped patterns. The glaze works really well with those kinds of treatments.

What many glazes do not do well are larger, smoother surfaces. Some of them puddle oddly on them, while others just do not show enough contrast. Horses, with their big muscle masses, have a lot of flatter surfaces, so glaze that can look great in another application might not always flatter them.

So the pendant mold became my favorite way to see how a given glaze formula might work with a horse shape. The ones in the above picture are my glaze chips. They have a bail at the top like a pendant, but in this case that is so I can hang them as a group on a cord on the wall of the studio. The glaze formula is written on the back of the pendant, so I can pull whichever I need and recreate the color.

Back when I was shrinking the Celtic Pony medallion, I also shrank the pendant. The pendant was already small - only 1.5" in diameter - so mostly I was just trying to see how small I could go before the detail was lost. I ended up with an image around 18mm in diameter.

At the time I thought the size might work well for a bead, but the design was too thin to run a stringing hole. The other option was to punch holes in the sides of the design so that links could be fashioned, but the only open areas (behind the neck, under the chin and below the forelock) would tilt the head at an rather strange angle. That's when I decided to weld two mini-pendants together back to back. That's how the bead above is made. The stringing hole runs down the center between the two sides. It worked, but it was far too time-intensive to make, and far too easy to squash the design while trying to manipulate the two sides together.

That was the point at which I set the project aside, thinking that it was educational to shrink something so small, but that nothing practical was going to come from it.

That was until I ran across some base metal bezel settings. I love the recent jewelry trend for using antique copper and natural brass, so I often check out the new offerings. When I saw the copper bezel setting (second from the right), it struck me that it was probably the same size as my tiny pendant. When I brought it home, I could see that it was just a millimeter off (17mm). I was able to trim the pendant in the greenware stage, but I did wonder if there were other setting sizes available online (17mm seemed like a "off" size to pick). Sure enough, there were a variety of settings with 18mm being more typical. The first and third pendant in the picture are 18mm antique brass and copper respectively. The last pendant is one of the 1.5" originals (taken from my glaze chip cord).

Here is a close-up of the copper version. There is another setting style, but I found that it was just a fraction too small so the pendants would need a slight trim to fit.

I am looking forward to making some jewelry with the pendants. I love the look of the pottery with base metals and silk cording. For those that haven't seen this type of jewelry before, I'd highly recommend the Vintaj website. It is full of wonderful products and ideas, as is their blog.

Sunday, July 4, 2010

Summer time!

All the kids have been away at camp these last few weeks, including my pony, Sprinkles. The barn where I board her hosts a summer camp, and we thought it would be a good experience for her. She is a favorite among the campers, and certainly loves all the attention. In the picture above, she's been "decorated" with Carolina blue handprints for the show the kids put on for the last day of camp.

Of course she also needed lots of blue ribbons to complete the picture!

She is also - finally - roaning out. Sprinkles is a suppressed leopard, which means that over time her forehand will roan out to reveal more spotting until she more closely resembles a true leopard. In the right light, the spotting on her face is now visible but I decided to wait until she wasn't done up in blue paint to try to get those pictures.

Everyone being occupied with camp meant that the house has been really quiet, so I took advantage and logged some long hours in the studio. Unfortunately for the purposes of the blog, much of that time was spent cleaning the mounds of greenware that had accumulated. Just as I occasionally find the clutter in the studio is more than I can tolerate, I reach my limit with the castings. It isn't very interesting for the purposes of blogging, but clearing the greenware shelves is great for a sense of accomplishment. (This was a good way to combat the frustration I have felt about not being able to finish the books in time for this year's BreyerFest.)

In addition to clearing the shelves, I also made a fun discovery about a small project I had abandoned sometime last year. It had not worked as I envisioned it, so I set it aside. It turns out to be perfect for another application. Once the final results are out of the kiln (with luck, that will be tomorrow) I will post it.