Stages of slip

As I blended up an ice cream container of slip for my Mishima experiment I thought perhaps I could use some of it for slip painting. I used a humble paint brush to apply this slip to a damp leather hard greenware cup. The design is quite course but I’m hoping to add some finer details after the bisque firing. The benefit of adding my design at this stage is it will be stable during the glazing stage. I can put as much runny glaze on this as I’d like and these blue leaves will go nowhere.

As this is tinted slip, the design is slightly raised. I’m going to rub these down once it is perfectly dry to ensure it has a good hand feel once fired.

.....

This cup sat on the shelf as I continued my stained slip experiments. I ended up filling a tiny squeeze bottle full of this slip and trailing on some stems. The finer detail really helps. I quite like the added dimension to the texture too. Now I’m looking at the photo, I really should have used a sharp tool to sgraffito some lines into the leaves. Ah well.

I’m hoping this stain won’t move after the bisque firing. It’d be a great way to avoid running of the detail. Then I could use the blue over glazes with abandon!

Mishima

I’ve been following a YouTube channel called Karen’s Pots and Glass. Karen’s is a ceramics teaching and during the covid restrictions she has been creating daily videos for her students. She demonstrates a lot of different techniques and introduces new concepts rather well. I thought I’d give a recent technique a try - Mishima.

Mishima involves cutting a design into a leather hard item and then back filling the design with coloured slip. The slip is then scraped away to create a flat surface for bisque firing.

I haven’t fired this yet as it’s been a bit wet and I’m not 100% sure it is dry enough.

Initial thoughts:

I probably should have learned to carve clay first. I need some better tools as a twisted bit of misc wire really isn’t the best cutting tool. I’ll be investing in a tiny little diamond shaped tool next time I visit Potters Market!

I made the slip by blending in some stain (not mason stain) with my stick blender. It hasn’t blended perfectly and there are still occasional dry clumps of stain. Consistency is good so I might try some slip trailing as well.

The slip was too shallow in some of the grooves as it shrunk slightly as it dried or slumped into the lines. I’ve gone over some of them a second time to address this issue. I think using a paint brush instead of a rubber bulb might be the solution for this.

I had trouble maintaining a smooth surface during scraping. I’m going to have to go back and ‘sand’ the outside of the cup with my fingers to remove evidence of the scraping. I doubt there is an easier way to do this apart from reducing the amount of excess slip and thus lessen the scraping.

I think this will make a great layered glaze. I’m curious how it’s go with runny over glaze. Perhaps I could preserve my beautiful delicate black outlines in the bisque firing then runny over glaze will not deform my design. If I didn’t mind the dints, I could arguably achieve something similar by brushing the under glaze onto the leather hard green ware then wipe it off again. Something to follow up!

Let there be Light?

My first oil lamp - essentially a thick bottomed bowl with the sides pinched in and sealed. Glazed in a yellow outer with a clear semi-gloss coat to seal the interior. A simple triangle pattern was carved into the greenware prior to bisque firing along the foot.

A bamboo torch wick and citronella oil for firing, both purchased from Bunnings. Due to the kink in the neck the wick was a little tricky to insert but this does prevent the oil from sloshing out the front.

The lamp was pretty easy to fill and the wick adsorbed the oil very quickly. I cannot completely fill the reservoir as the wick lip is around the same height as the rest of the bowl so oil will seep into the open and pool under the wick.

This lamp produces a rather large flame when lit. This could be related to the loose wide weave of the wick (too large), the protrusion of the wick (too long) and partly, the strong wind. I'm going to modify what I can when it's less windy and see if I can get this to be sufficiently manageable that I'd risk having it inside.

I may have to carve a dragon into one of these.

Not medieval shading experiments

I really wasn't sure how this would turn out. This is a rather short cup and I wasn't sure how to decorate it. I was cruising around Pinterest waiting for some inspiration to hit and stumbled across some beautiful mendalas. Eager to try some of the shapes I'd seen, I used multiple shades of blue and blended them into each other. I then went over with some  dots and lines to provide an additional design element. Most of the blue came out darker than I thought it would and the light blue dots are a little thick as they were applied with a paint brush. Still, I'm rather happy with the outcome.

One of my friends said this looked like snow so next time I'll trial some snowflake designs in the blue instead.

Green globe attempt 7

There is no extant item to go with this globe cup as I designed it myself. I'm quite happy with the light/dark balance though I wish I'd learned the 'do not underglaze the rim' lesson before I completed this one.

All fired. The image is a little blurry but some of that is due to the glaze running slightly. Still, I'm quite happy with how this turned out.

Green globe attempt 6

I fell in love with this pattern. I cannot find this extant bowl anywhere though. I can't even find it in any of my Pinterest collections which baffles me. I know I had this saved as a post-to-be on this blog but I can't even find that now. Even Google image search has failed me. If you know any of the details of the image to the right please comment!

On the left is my copy of the motifs. I really like the balance between the thin lines and the thick ones here.

Overglazed in sea green then transparent green and fired to stoneware. This came out lovely, I'm so happy with this cup!

Green globe attempt 5

This was my 5th attempt at a green globe cup. I think I have figured out the difference between batch 1 & batch 2. Batch 1 was glazed at peak summer just after 12th night. Batch 2, glazed about a month later during cooler weather. As a result, a lot of the water from the first mid-green glaze didn’t evaporate before I dipped the cups in the translucent green. This meant less translucent green so a lighter frothier pale green. This time the first coat was given more time to dry so more of the translucent green glaze stuck. It provided a better green colour however the translucent glaze has a fair amount of silica in it so too much will make the glaze run and smear the under glaze.

Kashan cup with stylised vegetal decoration and inscriptions under a transparent turquoise glaze, Persian, early 13th century. Sotheby’s. Arts of the Harvey B Plotnik collection, item 177. There is also a slightly fancier version with slightly different proportions in the Victorian and Albert museum here.

Pictured above is the extant ewer whose pattern I have utilised. Per standard, I haven’t even bothered replicating the text as I do not know what it says nor do I know what effect an imprecise replication could have. I just loved how well balanced this design was and wondered if I could manage something similar. The original is 12cm high while mine is only 8cm, two thirds of the height. Skipping the basal section seemed like the right approach to maintain the shapes and ratios. I think it has worked out quite well.

The design in black under glaze. This was quite fun to do as the pattern wraps around the bulb of the cup quite nicely.

Fired. A small amount of running has obscured parts of the design. An interesting lesson from this cup - do not underglaze the rim. On previously posted green glaze cups it is possible to see the rim of the cup has very thin glaze. This section is usually pulled out of the glaze dip last and while thin, has the most time to accumulate glaze. As it is at the top of the cup during firing, it also is the first to have the glaze run. The sort of metallic shades to the rim on this cup is due to the glaze running and collecting the black underglaze. This has given it an interesting sheen. Though this is an easy way of treating the rim and makes a good visual border, I won't be using thick bands of underglaze like this again.

Fishies results

A short post about the creation of this item can be found here. I'm really happy with how this green turned out! These fish are lovely. There's a little bit of movement due to the transparent green glaze being so mobile but it's still turned out nicely.

Not-a-globe but still green

Finished - green glaze conical cup with black underglaze in the style of 12-13th century Iran.

I've been focusing on achieving balance in my underglaze pieces recently. It is an interesting challenge to even out the light and dark space as well as the thick and thin lines. I was intrigued by this extant cup (below) as it has so much black yet still achieves a balanced finished look. I wondered if I could replicate it and if the lighter green I've been using will still do it justice.

Left: black underglaze. Sketched in 8B pencil then hand painted. Right: Extant cup, 12-13th century, Iran. Harvard Art Museum. Item 1936.48.

Even though the green ran a little, I'm pretty happy with how close to the extant item the colour is. The cup probably needs to be a tighter cone shape with slightly thicker walls. This unfortunately deformed a little in the kiln losing it's pleasing circular shape. It's still viable just not as perfect. A solid 7/10 in my opinion.

My little friend

I moved out of Leederville over a year ago and I was quite sad to no longer interact with the Willy Wag Tail I'd tamed while she was hatching her eggs on my porch. Happily, the new house has a WWT who is even more tame and demanding. He followed me into my basement to demand mealyworms from me even though he'd already had two snacks that day. Isn't he cute?

Green but not like the others

Wheel cut glass bowl. Persian (Syria? Iran?), 10th Century. Sotheby's - Arts of the Islamic World. 5/10/2011 lot 203

I thought I'd try something a little different. I love the extant article, the way the light shines through the carved design is simply beautiful. I have tried to capture the design for the green-black series but it's not quite as effective.

This is the cup post glazing. The small crack in the rim has been sealed with the glaze. I double dipped this one in the transparent green glaze and you can see it's had quite a runny effect. While it doesn't do my underglazing any favours, the transparent green running off the sea green has created the most delightful sparkles on the inner rim. There's also a pool of transparent green in the center of this cup which is beautiful. Not what I wanted but some nice colour play all the same.

I plan on attempting this design again at least twice more. Once I'll carve to allow the glaze to pool and thicken in areas. The other I'll practice hydro-abrasion on and have more prominent areas raising up out of the glaze. It'll be interesting to see which is the most effective with this glaze combination.

2 level hydro-abrasion

I got impatient while waiting for the previous attempt at hydro-abrasion to be fired. So I started on the next project. The aim of this one is to create some depth in the design by applying the shellac, removing the clay, then repeating.

Step 1: design. I used a medallion motif from a broken plate. I don’t like the central design on the plate but I thought the medallions were charming. The leaves are a common motif of the time.

1200s, Seljuk. Iran or Syria. Cleveland Art Museum 1915.590.

This is the design after the first layer of shellac. I love the golden tone!

I used a scalpel to trim away unwanted shellac before abraiding. It is really important to angle the blade away from the shellac so it isn’t under cut. I found some of the thicker areas tore if I wasn’t careful. This is probably because this isn’t a new knife blade and may be a little dull.

This is the cup after the second layer has been applied and a raised. As you can see, I shadowed the outer loop with a second layer and added a small arrow leaf in the middle / top. For comparison the two medallions on the bottom haven’t been a raised yet.

With 8 design elements to raise, I found was really important to stop and let the cup dry after every 2-3 items. Otherwise the rim was absorbing a lot of the water and getting squishy.

This dark blue glaze was very thick and it took forever to dry. As you can see it's reasonably runny so it pools nicely in little pockets. I do need to be aware of it along the foot though as it threatens to spill over and cement my piece to the kiln shelf. I'm really happy with how this came out even though I wanted the second, lower level to hold more glaze.

Basic hydro-abrasion

Recently I encountered a fellow potter at Claymake. She had the most lovely relief patterns on a cup. When I inquired how she'd achieved such fine lines she told me she was experimenting with shellac resist then removing the clay body with water. She couldn't tell me much more about the process so I decided to google it. I couldn't find any videos on Youtube but there are a number of ceramic boards which make some interesting reading. One board suggested using shellac as a resist as it's a naturally derived product that will burn off in the bisque firing. The following is my initial experiment and thoughts.

The only brand and smallest bottle of shellac available in the store. It would have been cheaper to purchase shellac flakes and make my own but there were no solvents available so I couldn't.

A slightly skewed cup. I picked it up when it was too damp and it tilted. Still usable and if not for this experiment it wouldn't have been fired.

Step 1:

Use a paintbrush to apply shellac to dry greenware. The greenware will adsorb all of the alcohol and the shellac will dry really fast. If you want finer lines, leave a small amount of shellac out in the sun to thicken for half an hour or so.

Thoughts - the shellac applies well but when it is the thickness of water you either need to only have a small amount on your brush and keep dipping and wiping or use a thicker consistency. If you don't, drips of shellac will spread making thicker lines and blotches. I like the golden shine and can see why this is used on furniture.

It occurs to me that stencils could be used with technique if the shellac were slightly thicker.

Step 2:

Use a wet sponge to wipe away clay from around your design. This is called hydro-abrasion even though typically that term is applied when using pressurized water. Circular motion of the sponge seems to prevent one side of the line from getting too much lower than the other. When the clay turns to a slurry, use the other, sopping, side of your sponge to wipe the clay away. Work on one area then move to another.

I used a brand new dish sponge. Under the sponge is a bit I've already done, the other three clouds still need attention. It's reasonably easy but I did get clay water everywhere.

Thoughts - This may work better as a staged step. I found that the water had undermined the strength of the cup. As I posed and held the cup my thumb has created a small divot in one side while between my fingers a small crack has formed. I think I managed to fix both but I believe that I need to reduce the amount of free water and probably do one side, wait for it to dry then do the other side. In the image above you can see a small area on the bottom cloud where I've accidentally wiped away the shellac. I believe this was because it was rather thin in that area. The thicker shellac, the more golden areas, seems to have held up fine.

Step 3:

Bisque fire it.

Thoughts - It came out well. I'm really happy with how the relief works. I think it'll show off a glaze nicely. I also think this could be a substitute to create once off tiles patterned off molded items.

Step 4:

Glaze & stoneware fire it. I chose midnight blue glaze with a clear overcoat.

Thoughts - Love this look. Next time I'll use a thicker cup and try a two layer design. I think this may work really well for some heraldic displays similar to those carved in marble. I may also try a colour resist. After the first wash, I'll place some englobe or underglaze on the cup and then apply a second coat of Shellac.

#not-so-pro tip: hydro-abrasion works best if the sponge is run parallel to design. Right angles creates more of a sloped edge and it is harder to achieve a clear difference in clay body level.

Green globe cup attempt 4

13-14th century, Syria. The Met Museum. Accession 56.185.8

I thought this design would translate nicely.

The bisque was underglazed in black using two brush sizes and a thin squeeze bottle. That variation of line thickness really helps this design. This will be dipped in an opaque midgreen then overglazed in a deeper translucent green. I'm really happy with how this design came out. There are some minor errors but nothing that detracts from the design.

Non-medieval hydro-abrasion fun

Front

Back

Not everything needs to be medieval. I thought these designs would provide a nice balance between thin and thick glaze. I suspect the lobes will work better than the vines with a simple overglaze dip so I’m going to use a sponge to clean up the vines and see what happens.

Lobe cup. I quite like this one but I think next time I’ll have some elements coming up from the base of cup as well.

Glaze pallets

I made some glaze pallets so I could see how well the various colours worked on stoneware and the difference between the local buff clay and pb103. I’ve done this in the past, creating two test tiles with and without a titanium white base glaze.

It was important to make some new tiles because I’ve purchased some new colours and I needed to see what the impact of multiple layers was. These will be critical to making the colour choices for an upcoming collaboration.

Left- PB103, right - buff. Each divot is top third 1 layer, middle 2 and base 3 layers. The top 20 colours are the Chrysanthos glazes. The bottom glazes are five selections from the Glazeit pallet which I suspect are Duncan underglaze. Black is Cesco ebony brush on underglaze.

Practices makes perfect

I found a lovely cup on a viking related blog (Bjornthisway) and thought it was the perfect thing to aim for to continue developing my skills. This cup resides in the Sydvstjyske Museum in Ribe. The main features of this item are straight sides with even walls, a lip and probably, a tight square internal corner.

I'm getting there.

Kashan fish cup

I don’t really care how the overglaze on this one turns out. I’m already very happy with how this design has turned out.

I copied this design from the bowl above. I’ve found two images of it but other details are slim. It is captioned ‘ Bowl with fish (late 13th to mid-14th century), Iran, probably Kashan. Stonepaste; black decoration under transparent turquoise glaze. The Hossein Afshar Collection’. I’ve found a similar bowl at the Art Gallery of South Australia here but it doesn’t have quite the same fishy swirl.

This is going to look amazing once it is green!

Blue hats of MS 6613

Hats of MS 6613 - a safavid manuscript with many lovely illuminated pages

These images were gleaned off multiple pages and there are a few similarities across the board:

• Bright sky blue hats with white dots - These may or may not be spangles as they  occasionally appear to raise off the edge of the hat.
• Black decoration around brim - this looks like lace or fur floof
• Brim - the brim is at least half the hat tall
• Point - the point is slightly rounded may be floppy given the multiple directions it moves.