Thursday, 18 June 2020

Follow up - hydro abrasion fun

I previously posted two greenware cups which I'd decorated with hydroabrasion designs. I have now full glazed both of these and am moderately pleased with the results.

The first cup was dipped in midnight blue. This glaze is tricky because it's very thick and dries slowly. As it is translucent, it is very difficult to avoid finger prints unless you are using tongs to dip the cup. This only had a single coat of the blue as I was concerned that it'd be too runny and end up flowing down the foot. It has pooled there somewhat but has behaved remarkably well. I am curious if I dipped the rim to bring more colour to that edge, would I see a line?

This second cup was dipped in midight blue. This was then followed up with a aubergine rim. This really displays how runny the blue is as the line of the rim dip isn't smooth with a beautiful organic movement. I quite like this combination even if this isn't a medieval design. I also quite like the effect of the small divots in the flower design. This has created small dark pockets while the main form is outline in the white. This is a really effective three toned colour grouping. I will be trying this again.

Monday, 15 June 2020

Pleasingly accidental

Every now and again, a mistake is made that must be preserved. During my first ever throwing class, I accidentally destabilized the wall of a shallow bowl. I kept the pot because the ripple was quite pleasing and I wanted to see if a green-purple combination of glaze could emphasize it. Occasionally, a flaw can be a feature.

This cup was throw right before the COVID19 social isolation kicked in for my state. Its walls were quite thin and the clay had been thrown multiple times as I'd had a couple of failures that evening. As a result, the clay was very wet so wasn't holding up well. As I pulled, I thinned the base a little too much and it couldn't hold the weight of the rim and collasped on itself. It was an almost even collapse with four main divots so I thought I might preserve it. The rim was almost even as well so it is a reasonably viable drinking cup.

I glazed the inside with satin white and the outside with aubergine over midnight blue. It has created a lovely purple blue blend which I'm going to try to emulate more. I think if I do this combination again on a thin cup, I might double dip the purple on the rim to hopefully prevent too much colour creep away from this thin edge.

Friday, 12 June 2020

Riffing on blue

Four versions of a theme

I recently started working with blue glazes again. I find them so much more visually pleasing and I feel they a much more striking. In an earlier post, I displayed my first Back to Blue cup. Once this was complete and before it was gloss glazed I was so pleased by the balance of the colours I thought I'd continue with that project. I have now produced an additional four cups. I feel they have varying stages of 'medievalness'. By this, I mean they tend to drift from the original source material through the use of colour and the placement of the design elements. I think the smallest cup is now my favourite but this exercise has been a really good exploration of how far I feel it is acceptable to wander with the use of design elements and still present something I'd be happy to call medieval.

First up is a tiny cup with a slight taper. This is half a step away from the original source material. The leaf forms and distribution remain true to the original designs. The main changes are the lack of secondary design elements. If this were more period, the background would be full of smaller interwoven buddy vine and swirl shapes and the spiral fill would be minimal. This is my favourite of the three because it still feels like it could be Kashani.

Three quarters of a step away. I then created a larger cup with better vine branching. There are less leaves in this design as well. I was thinking of continuing the spirals into the lower half and making a semi-matching set between the large and small cups but I wasn't sure. I consulted my brains trust (Brooke in this case) if I should do spirals or the more modern solid blue. As I was torn, I went with her suggestion. This is still half a step away because some of the extant objects have blue backgrounds. Again, for this cup, I have eliminated the secondary design elements. I have also chosen to segregate the dark blue half of the cup which I feel is a more modern aesthetic.

The final cup started out as a very period design - vines inside a lobe shape. I repeated this design three times around the cup because four resulted in skinny slivers and two had too much space between them. If I could have made four work, I might have flipped them in opposite orientations as I've seen on some period items.
I was a bit stuck on the best way to link them together. I decided to continue the solid blue theme and fill the background. I soon realised that this would be a little overwhelming so I added a small leaf cluster in the blue. I also felt that the design was a little too stark but I didn't want to use blue shading as I had on the other cups because I was afraid it's detract from the size of the leaves. Instead, I added three dark blue lobes within the design to link the white section to the blue. I think it' worked reasonably well but the stark divide between the lobe and the rest of the cup is again, another step towards modern. I also thought I'd try to tie the secondary vines into the design again by switching out the spirals for an unplanned viney tangle. As a background pattern its chaotic nature is quite pleasing and really helps the eye skip over those sections. I tied this together with the blue area by filling in the leaf cluster with a similar pattern. This is the most modern of the set of four and the largest

Here is the view of the leaf shape. Note the white froth at the base of the cup? The blue underglaze fills the pores of the clay body. As a result, it won't hold as much clear gloss glaze. The glaze tends to run off or not bond as well as I wish it would. As a result, these solid underglaze areas turn out more matt than glossy. It does create a rather pleasing texture and a nice contrast between the white and the blue areas but I think I'd rather a full gloss. This is a problem for my fully coloured arbarellos as well so I need to find a way to resolving this. I'm not sure if this means dipping the body, waiting days for it to dry fully and then dipping it in clear again. I am worried too much clear gloss will smear my lines. This is an experiment I'll have to undertake with a small cup so it doesn't take me forever and a day to decorate it.

Tuesday, 9 June 2020

The final globe

This is the final globe cup from my green series. I decided I needed to further expand my use of the medieval motifs and thought maybe for the final cup I'd step away from the green over black. Instead, I used the period motifs and modified to them to align with a more heraldic colour set.

After glazing in the rim decoration and the three cats in ebony, I decided I wanted to move as far from the green as possible. I thought this would be a really good project to trial my new Firetruck Red glaze performance. I retained the motifs of the extant cup with the striped half base and the vines but used olour to emphaise the design. The red glaze is a beautiful colour and I am really happy with how this design turned out.
The dimensions of the cup are more bulb shaped rather than the tapered look of the extant jug howver when handled, the elements tie nicely in together so I am satisfied with the look.

Jug with running animals. Kashan. 12-13th century. Cleveland Museum of Art. 1947.495

Saturday, 6 June 2020

Back to blue

I've spent a lot of time working with green overglaze these last few months. This was partly driven by the need to round out my skills with regards to my 12th night Arts and Sciences entry. While the green has been fun and I've enjoyed the new design elements, I must admit I find blue much more appealing. This piece was thrown during Covid19 lockdown times in my little basement workshop. I used PB103 white clay so I could avoid adding the complication of white underglaze. This piece has been fired to stoneware.

This piece was inspired by my previous arbarello collaboration piece. I rather liked the background fill and the use of white elements to balance the darker blue. I used 'Colbalt blue' underglaze for this one which is a much deeper, and delightfully dark blue. I do prefer the lighter Electric Blue I think but this is still pleasing.

Instead of copying a pattern direct, I thought I'd combine multiple design elements and continue my 'balance' project. I was largly inspired by the above asymmetric vine design. The image isn't amazing quality and remains quite fuzzy even when zoomed in which is unfortunate. I took inspiration from the vines as well as the white / black / blue balance. I've tried a number of versions of this which I'll post in future blog updates.

The design is symmetrical with a 1/2 division of the cup. after layering the underglaze, I dipped it in clear glaze. Once dry, I then carefully rubbed glaze with my finger tips to ensure no air bubbles had formed. This seems to have worked really well as this cup has excellent gloss coverage. I am really happy with how this cup turned out!

Wednesday, 3 June 2020

Slip dots

Squeeze bottle of stained slip became snow-flakey decoration. I’m loving the dots. They flattened during the final glaze and the clear around them is a little thicker but I think it has worked well.

Monday, 1 June 2020

Making an impression

While rummaging around in my tool drawer trying to ring the right screwdriver I happened upon a leather stamp I’d bought years ago and never used. I wondered if it’d work well on clay and since I had a slightly less than leather hard cup just sitting there I tried it out. This cup will have sea green base with translucent green rim which will hopefully run and fill the leaves nicely. If this works it’ll open up a whole range of stamping options for me since these would also look good impressed into little clay buttons attached to a cup.

Friday, 29 May 2020

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!

Thursday, 21 May 2020


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!

Monday, 18 May 2020

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.

Friday, 15 May 2020

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.

Wednesday, 13 May 2020

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.

Sunday, 10 May 2020

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!

Thursday, 7 May 2020

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.

Monday, 4 May 2020

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.

Friday, 1 May 2020

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.

Wednesday, 29 April 2020

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?

Tuesday, 28 April 2020

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.

Sunday, 26 April 2020

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.

Friday, 24 April 2020

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.

Saturday, 18 April 2020

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.