More fun with slip!

 

I've been doing demos for my class of a fun & spontaneous way to work with trailing slip, by applying it directly by hand. The vase above was decorated using a hand-application method. I've been having so much fun with it that I decided to created a limited line: mugs, bowls, plates, tumblers...maybe a sugar jar & butter dish. I want to keep it limited, because it sometimes happens that I get fascinated with a technique for a few months and then suddenly, abruptly lose interest in it - so I don't want to offer this to my accounts only to discover in idk March that I'm painfully bored of it! 

I've started working on how the mugs & plates will look, and I need to think about an interior glaze...maybe a periwinkle color I've gotten in the past by adding Mason stain to my basic white.

 I posted a video for paid subscribers at my Patreon page on the slip application technique. 

In other news, the firing I unloaded last Tuesday was very good! The draw rings have really evened out my game; no more over-glazed, pitted work & no more dry, gritty pots. Most of those will go to stores - I just packed up inventory for the Maine Potters Market & the gallery at Portland Pottery - but I expect to have an update to the online store this weekend.

We've been having a stretch of amazing weather this autumn here in Maine, so I'll probably take Wednesday to enjoy it with Doug. Photography Thursday, shop update maybe Friday. 

Rings of Fire

My loopy little friends

Since I built my first soda kiln in 2010, I kinda got out of the habit of using draw rings. I had the old kiln so dialed-in, so I didn't need them, then it seemed like too much trouble after we built the new kiln. 

My last firing, though? was not great. Everything was gray, and there was some pitting & blistering of the soda glass. The pitting is its own problem - Jeff Zamek has some thoughts on that - but the gray coloration is simply too much soda. Though I (obviously!) weigh out the material so I use the same amount each time, last firing I used my new, snazzy sprayer, which unlike the old one was able to spray all the liquid into the kiln, instead of leaving a few inches in the bottom. Also, without thinking I used hot water, which can hold more soda in solution, so I may have inadvertently sprayed more soda into the kiln than usual. 

I have some ideas of how to correct my unhappy result, but instead of just guessing & hoping, I'm going to employ a technique used by smarter potters than I am: draw rings! These small, looped-shaped bits of clay are placed near a spyhole so they can be drawn out during the soda process, to assess how heavy a coat of glaze has accumulated. I actually have not used draw ring since graduate school, so this should be interesting.

They are cooling in the bisque right now, along with the pots for the firing. I plan to make a little video of this process for my Patreon page - click here to subscribe! 

Balloon Rounder

I can't take credit for this one - learned this from my students (who maybe got it off Pinterest? don't know.) It's genius, though - the balloon is squishy enough that as the pot shrinks it compresses, so you can just leave it in, keeping the pot round as it dries.

To be fair I have not tried this myself - as I was typing the last paragraph, it occurred to me that the balloon *might* be squishy enough to distort right along with the pot, if say, the pot dried to fast or something like that. 

Anyway, it's any idea. I will let you know how this student pot turns out.

FINALLY: Mug Rounders 4U!

Remember, like, a year ago (no, it was more than that...) when I told you I'd made myself a new tool? The Mug Rounder works like this:

This looks like a job for...The MUG ROUNDER!!

Oooo, look it's round again!

Press it in, lightly collar the rim inward towards the rounder, give it a little spank & a twist, and presto! Your inadvertent wonk has been corrected. (Also a good option: Embrace the Wonk!)

If you throw, you could easily make one, of course, but if you don't, or just don't feel like making your own, waiting through a bisque cycle, etc...you could always buy one of mine! I finally got around to listing them in my online shop. To be fair to myself, the main reason I didn't was because I was selling them to friends & students. I've caught up with the lucrative people-I-know market, so now I can offer them to the world at large. 😊

Wax Erosion

I've been demonstrating this technique in my classes this week: wax erosion. The short of it is, you apply wax in an image or pattern to bone-dry ware, then wipe with a sponge. Wherever the wax is will not erode, wherever the wax is not will. This creates a low-relief surface. You can do several layers - foreground, middle ground, background - for an illusion of depth.

Starts with a porcelain greenware cup

First layer of wax

I want to say a word about wax, here. I've used paraffin in the above picture, but the cup at the top of the post was made using water-based wax. The paraffin is harder and doesn't rub off as easily, but it has drawbacks too (besides fire danger) which we will see in a minute.

After rubbing with wet sponge

I wipe the surface of the pot with a wet sponge. The wax resists the eroding action of the water, while the clay around it gets worn away, leaving a raised pattern. Careful not to use too much water! If your greenware absorbs water too quickly it will crack.

More wax, on top of or around the first wax

More wiping...

Now, waaay over do it & wipe right through the wall of the pot!

You can skip that step if you don't feel like being a giant fuck-up. This, though, was the disadvantage of the paraffin wax; because you can wipe away a lot of clay before it starts to remove the paraffin, wiping all the way through the porcelain is possible. That would be a lot harder to do using water-based wax, because you either have to create a much shallower relief, or stop every minute or so, examine the pot, and re-apply wax where it has begun to erode.
Here are the two side by side! Water-based wax on the left, paraffin wax on the right.

 The wax - either kind - will of course just burn away in the bisque. I'm thinking celadon or clear glaze, or maybe just let the soda vapor do its thing.

Trimming Hack: Throw a Wet Clay Chuck

I enjoy almost every aspect of ceramics. I love throwing, I love handbuilding. I love pulling handles and stamping and slip trailing. I love glazing, and loading the kiln, and firing. I can even enjoy the quiet focus - the zone - of mixing glazes.

What's missing from that list? I do not love trimming. I find it tedious, so anything that I can throw without a trimmed foot, I do. Bowls need to be trimmed, because the extra clay is holding up the curve of the bowl while it's still wet. Cylinders, on the other hand, I can get all the clay up into the wall, and pull the whole wall to the thickness that I want.

And that's a good thing, because cylinders are a bear to trim - anything that the rim is not the widest point is more difficult. Nevertheless I occasionally get a whim - or a compulsion, more like - to make mugs with foot rings. Cylinders, in other words, that need to be trimmed.

Like yesterday! So today I had the job of trimming these shapes which, when placed rim down on the wheel would have high centers of gravity & little stability. Here's how I deal with that:

First, I center a hump that is narrower that the mouth of the mugs at the top, and wider at the bottom. I's also taller than the interior shape of the mugs.

Next I place the mug upside down over the hump, adjusting it this way & that until the bottom is horizontal and the mug is centered. Then I give the bottom a little spank, to suction it onto the hump. 

Then I just trim as usual. This photo is deceptive - trimming is a 2-handed operation for me - but I needed one hand to hold the phone. 

And, boom, foot ring. 

If your mugs are not all the same height & width - I was playing around with different proportions yesterday - you can just recenter the same hump a little taller or wider or whatever is appropriate for the next pot on deck.  

Demo: Thrown Vase with Contrasting Clay Spirals

This was the demo I did for my Tuesday night class! A couple of notes about this:

1. Clay matters! In addition to their contrasting colors, you want to use clay bodies that fire to the same temp (thanks, Captain Obvious!) and have approximately the same shrinkage rates. 
2. No matter which two clay bodies you choose, let your vase dry slowly. 
3. It's not shown on the video but after the vase became leatherhard, I trimmed the rim a bit. Adding the clay makes the center imperfect, so it came up doing a bit of a hula. I don't always think of irregularity as a flaw; I've been known to exhort my students to "Embrace the wonk!" In this case though it just seemed distracting. 
4. The music quits about 2/3s of the way thru. Sorry about that! I could have spent more time tweaking it but decided the clay work was the important part. 

Enjoy!

Rice Paper Underglaze Decals

One of the joys of teaching ceramics is it keeps me exploring new techniques. This week I brought to class some rice paper underglaze decals that I found online. I got them from The Ceramics Shop, but they appear to be discontinued there, so I found the original source: Ying Zhou Rice Paper decals. 

They are so easy to use!! Choose a design, cut the shape you want, press on the pot; wet the back, pat it down, let it dry, peel up the paper. You don't even have to peel up the paper, strictly speaking, if you are using it on leather hard because it will burn away in the bisque. My students loved them - I did, too! 

Probably did not need this much water. I might should have just used a damp sponge or soft, wet paintbrush. 

I pressed down gently with my fingertips, because the surface was curved & if the paper is buckled at all, or there are air pockets between the decal & the pot, those spots won;t transfer. Wait about 10 - 15 minutes for the paper to dry a bit. Doesn't have to be 100% dry. 

This is a slightly different dish - the left edge isn't a flaw, it was cut that way. 

You can also use these on bisqueware. 

Obviously they will want a transparent glaze on top. They are said to be suitable for cones 04-11.

The decals are (I guess?) adhered to the paper with honey, so they have a shelf life, and they are somewhat delicate and need to be stored with care so they don't flake off the paper before you get a chance to use them. As delightful and fun as these are, I sorta feel like I am cheating, using a manufactured design. Next I am search for a company that lets me upload a design and make custom rice paper decals.

After I have played with these a bit more. 😉

Cut Paper Slip Resist

Another demo post I've had in the hopper for a while!

I like the look of a checkerboard pattern, but it can be a little too tight for my liking...and also (truth now!) a lot of work, to brush slip on each individual square. For a checkerboard pattern that's a little more dynamic - and also easier to achieve - I sometimes use squares of cut newspaper.

I cut several layers of newspaper at once. I don't usually measure but cut squares (or "almost" squares) about 2" each side.

This works best on leatherhard ware. Here's how it looks on a platter:

I keep a little dish of water beside me as I work. Dip each square in the water, then drag it gently against he edge of the bowl to wipe off the excess. Arrange the paper squares in rows, corner-to-corner:

 Go around with a fingertip and make sure there are no wrinkles or bulges at the edges that slip can get underneath, and that the squares are stuck down well.

Brush your slip over the surface. The brush strokes will show, at least a little, so consider that when you are applying your slip. I usually brush all in one direction.

 

When your slip has just begun to dry - just enough for the shine to fade - you can start removing the paper. The edges will be easy; for the inner squares I use a needle too to get underneath them to start peeling.

Since I started this blog post, like, a year ago, this piece is long since finished & gone. I glazed it with  ^10 shino & fired it in Portland Pottery's stoneware kiln. The slip fired to a blue-y black, the bare clay a yummy rust brown. Obviously a transparent or translucent glaze is a good choice here.

You could, of course, use any shape for your paper resist. With some care you can even do relatively delicate shapes. Torn paper makes for a nice dynamic line.

New Tool: Mug Rounder!

As you can see by the background, I've had this post in the buffer for a while! Sometime last summer, I made myself a new tool. (Actually made a whole bunch of them, thinking I might sell them, but I didn't get around to that either!) See, I do a lot of stamping and other alteration on my pots. I don't always mind if the piece is no longer round afterward- in fact sometimes it's the whole point! Sometimes I like the tension between the squishiness of the alterations, as with stamping, and the crisp machine-roundness that the wheel contributes. I found an easy way to get that back. It works like this:

Ooops, not round anymore!

No worries! Enter the Mug Rounder™ (J/K, you know I didn't trademark that shit.)
Gently press the mug rounder into the mouth of the mug. Once it's in place, give it a light spank. 

Et voilá, my mug is round once again! The mug rounder is just an enclosed thrown form. I made mine about 3 3/4" at the widest point, and they taper to accommodate smaller diameters, but obviously if you typically make wider-mouth mugs you could make one any size you want. It's only bisqued, because it needs to remain porous; otherwise it will stick to the wet clay and not release cleanly.

Hope you all are staying warm (or cool, if you are in Australia! Thinking of you, Tanya!)

Garden Inspired Slip Inlay

This time of year inspiration is right outside my door. Blooming now: purple coneflowers! Their simple and easily recognizable shape makes them naturals for slip decoration.





To do this slip inlay, I first painted my image with food coloring.

Next I coated the interior of the bowl with water-based wax. Paraffin will work, as well, but it is a little more brittle, so harder to cut cleanly through.

Once the wax dried, I carved out the image with a sgraffito tool. Then I brushed on a white slip - underglaze will work for this as well. The slip sticks to the carved surface, but beads up on the waxed surface. I used a rib to remove the excess slip - one of the red ones from Mudtools works great (I call them Gummy ribs...like Gummy Bears, get it? ) because it's soft enough not to scrape any of the wax away.

The wax will burn away in the bisque firing (Thanks, Captain Obvious!) I'll choose a transparent or translucent glaze t show my slip work to best advantage. I'm leaning towards a shino, but I could see this in Amber Celadon...

Garden Inspired

I loooove sliptrailing. Usually my sliptriailng is just dots or other patterns, but occasionally I get inspired to do some representational marks. Even the abstract marks are botanically inspired, and in June there is a lot of botanical inspiration to be had in my garden.

Bleeding hearts have tugged on my mind for some time. The simple repetitive shapes, the multiplicity, the distinctive foliage - they seem made for slip decoration. It's harder than it looks, though, and my first several tries were either just bad - blotchy, unrecognizable - or just didn't really capture the charm of the plants. Theses are a bit better, but I'll keep working on it.

The green you can see peeking out from beneath the slip is food coloring - I find it helpful to loosely paint out my marks. It saves me wasting slip by trailing, wiping off, trailing, wiping off, and so on.

These blossoms are loosely inspired by creeping phlox.

These are more generic but I think I could minimally adapt them to reference poppies. The difficulty with slip trailing is with depth - trying to represent some blooms or petals behind others can sometimes turn into just a blobby mess! On these last two the food coloring serves to mark out the spacing for the scalloped design - this has greatly improved my placement! It has he advantage over pencil or needle tool in that the lines are clearly visible but do not have to be removed later - the food coloring just burns away. 

Pop Quiz!

This is for the clay students reading this blog. I know you are out there!

My upside down plates have come out of the bisque, and guess what? One of them cracked pretty spectacularly. I sort of thought it might. Anyone care to hazard a guess as to why the one cracked and the other didn't?

Turn your computer upside down for the answer!

Actually, there's a bit more after the break.

Drive-by Post: A Demo in 5 Pics

Just wanted to share something fun I have been demonstrating in my classes this week: an underglaze decorating technique involving carving through a layer of wax to create an image and low relief texture at the same time.

It starts with bonedry greenware. Bone dry is better than late leather hard only because the water-based wax resist dries faster. I brush on a layer of wax; water-based wax resist is better than paraffin because it is less brittle, but either one will work. (Optionally, you could paint your intended design on the greenware with food coloring first, if you don't want to freehand it.) It needs to dry completely, which will take a little longer on greenware than it does on bisqueware. The rest goes like this:

Carve thru wax and into the clay with a sgraffito tool

Brush on underglaze

Second layer...

Wipe excess off with sponge

Do it some more...

This piece will get some more carving on the lid, then I will re-cover it with wax, allow it to dry, and then repeat the process with a different color of underglaze; I'm thinking white. It will be bisqued, which will burn away the wax, and then either glazed with a transparent stoneware glaze - maybe celadon - or I might just let the soda vapor do its thing.