Monthly Archives: September 2014

Wax Resist

One of the more underrated techniques for decorating pottery is use of wax resist. In all the classes I’ve taken, hardly anyone uses it and it’s damn shame. The reason this technique is so great is that you have a lot of control over the decoration of your pot and you can create some very intricate/delicate patterns.

On greenware wax resist is used to create a textured pattern. You paint it on bone dry clay, let it dry and then wash away the clay around your pattern. The result will be a slightly raised pattern.

Photo Aug 18, 9 14 32 PM

You can draw the design in pencil first, then cover in wax resist. Its relatively easy to apply with a thin brush and dries quickly.
Pro tip 1: when wiping away clay around the wax resist, wash the clay out of your sponge constantly. Otherwise you’ll just spread around a bunch of slip instead of removing it.
Pro tip 2: squeeze a lot of water our of the sponge when wiping away clay. With too much water you will wash away the clay from underneath the wax resist and your pattern will disappear.

Photo Sep 02, 7 52 06 PM

This is the result. You can see the design pop out of the piece. This works very well with translucent glazes. I haven’t tried opaque ones, but maybe it’ll look cool too. give it a try, let me know how it goes.

On bisqueware you can use wax resist to define borders between colors or control overlap.

Photo Aug 30, 2 45 51 PM

Example 1: glaze against unglazed wax-resisted surface: The text was written in wax resist and after the glaze was applied, i wiped down the cup. You can see the borders of the glaze came out really sharp.

Example 2A: Glaze 1 ia applied and partially wax-resisted those are the darker areas of red)

Example 2a: Glaze 1 is applied and partially wax-resisted (those are the darker areas of red after the wax resist dried)

Example 2: wax resist applied to define where glazes should and should not layer

Example 2b: wax resist applied to define where glazes should and should not layer. A second layer of glaze is applied on the whole piece. 
Pro tip 3: make sure that wax resist is completely dry before you paint over it. Otherwise you will not get a clean separation like you see in this pic.

Example 2B: you can see where the sparkly copper glaze wasnt covered by the green.

Example 2c: you can see where the sparkly copper glaze wasn’t covered by the green vs. where it was.

I hope that I’ve just inspired you to try wax resist.

If something I’ve explained above doesn’t make sense or didn’t work, please let me know in the comments!

Mug Study

I thought it’d be cool to do a study of what makes a good mug. In true pseudo-scientific fashion, I set out to work within a strict set of parameters and do a series of variations to see which one is the best. This post is strictly about the shapes that I made and how I think the shapes will impact the usability of a mug.  After they’re glazed I will test them on a set of parameters (below) and report back (with pictures). Obviously, personal taste will be important in determining aesthetic value, so please help me conduct my study by leaving a comment telling me what shapes you like.

The Judgement Parameters

  • How comfortable is the handle?
  • If you pour in hot liquid or microwave the cup with liquid, can you pick it up without burning yourself?
  • How consistent is liquid flow when the mug is tipped over?
  • Which shape is the most aesthetically pleasing? Leave a comment; let me know which one(s) you like best. If you can rank the top 3, that would be swell.
  • How much sipping control does the handle provide?
  • How stable is the mug? (How hard is it to knock over in an animated conversation?)

The Control Parameters

  • 1lb of clay
  • 4″ tall
  • 3.5″ wide at the rim
  • simple pulled handle

The Variations

  • each mug must have a different curve
  • handle shape to match the curve of the mug.

The Shapes

Photo Sep 23, 7 09 01 PM

Number 1: Slightly bowed in
I bet this will tip over easily, but it should be comfortable to hold and wont burn your knuckles if you’re using it for extremely hot liquids. Because it’s bowed in, the volume will be a bit less than in most other shapes. Liquid should pour out smoothly.

Photo Sep 23, 7 09 19 PM

Number 2: Top heavy
This one has a decently comfortable handle. I don’t love the shape and I think it’ll tip over somewhat easily. We shall see how it pours.

Photo Sep 23, 7 09 51 PM

Number 3: Flat vertical
The only way to place the handle in a way that this mug doesn’t look factory-made is to place it on the bottom, adversely impacting handling of the mug. This one would probably be good for moderately hot drinks that you want to cradle in your palms. It looks kind of masculine and I dig it.

Photo Sep 23, 7 10 01 PM

Number 4: Slightly bowed out
This has a nice large handle and the liquid shouldn’t accelerate too much when pouring out. I’m not in love with hos the shape looks, but it’s a solid mug from a practical standpoint.

Photo Sep 23, 7 08 46 PM

Number 5: Bowed out towards the bottom
To compliment the shape of the body, the handle needed to be taller and narrower. I like the look, but question the practicality. You can’t get too many fingers in there. Pouring should be easy.

Photo Sep 23, 7 09 30 PM

Number 6: bottom-heavy
I really like this shape. With the curve so low it should be very stable and has enough room for a solid handle that you can get a good grip on.

Photo Sep 23, 7 09 42 PM

Number 7: Whoa curves!
This one is weird and I bet the water pouring is going to be questionable, but the handle is very comfortable with those curves. You get really good control; of course, we’ll see how that goes with hot liquid.

Painting with Glaze

After a particularly long day in the studio I sometimes get questionable ideas. This is one of them. It’s questionable for a couple of reasons.

  1. I didn’t account for the fact that glaze runs
  2. I did 3 pieces at once with no testers

You’re probably thinking, “what the hell are you talking about?” I’m talking about using glaze like it’s paint. I decorated 3 pieces by painting an intricate pattern on them in glaze.

I wouldn’t say they look awful, but you can definitely see where the edges are all blurred. It matters also which glazes are next to each other. For example, I used Mirror blue on the bottom 2 pieces and that washed out pretty badly. The green didn’t have as much trouble.

Exhibit 1

Decorative Tea Cup
Decorative Tea Cup: design painted on with Burnished steel and  I put wax resist on the edges to keep it contained. That didn’t work!

Exhibit 2/3

These 2 pieces were inspired by Italian painted pottery but turned out totally NOT like Italian pottery. (The Italians must be using underglaze).
Photo Sep 09, 8 52 18 PMPhoto Sep 09, 8 51 49 PM

One thing I really do like about this whole painting “technique” is now green on top of yellow turned out. Perhaps if I had just stayed away from the Mirror Blue it would have turned out better. Live and learn.

Glaze Combination Test Cups

And now back to our regularly scheduled programming after that random Excel novel.

Remember when I was designing a honey-themed pot? I actually made it (will post more on that later) but didn’t have the right glaze for it. It can’t be too yellow, nor too brown, nor too clear. To look right it’s got to be the right shade of honey. This is a common situation in  my experience – where I have a few glazes that are kind of close to what I want but none are exactly right. Fortunately with low fire glaze, you can just mix the colors and they have a high probability of turning out well.

Of course, if you just spent however many hours making some intricate design, you don’t want to use that pot to test, though.  Hence test cups. Here’s the latest set.

1.Copper Adventurine + Clear

My goal was to achieve a honey-yellow color, ideally with sparkles.

Photo Aug 30, 2 46 55 PM

Outside: 1 layer of clear, 1 layer of CA, 1 layer of clear, all brushed on around.
Inside: Clear pre-mixed with CA

 

2. Hopefully Lilac

With this one I was aiming for a pleasant lilac color, not too purple, not too blue.

Photo Aug 30, 2 45 51 PM

Roughly equal parts of Larkspur and Blueberry spice, and 1.3 ish part Tearose, brushed on every which way

 

3. Glaze Layering Experiment

I wanted to see how well painted-on lines would stay and how painting one glaze on top of another woudl do. With these two colors you can’t even see where they’re layered.  (combination of the 2 mixes from above)

Photo Aug 30, 2 46 36 PM Photo Aug 30, 2 46 41 PM

4. Steel Boundaries

Bottom: Steel;  top: Tearose, Larkspur, Seafoam Green

Photo Aug 30, 2 47 06 PM Photo Aug 30, 2 47 12 PM

It’s a little bit hard to see here, but Burnished Steel turns into a cool dark green wherever it overlaps with a translucent glaze. I like! I also have a new appreciation for seafoam green. It’s a much more interesting color on here than it was on a test tile.

4. Orange Slice

The words are painted on in iron oxide. This is just a new glaze that I bought. Looks pretty plain, stable, orange-y.

Photo Aug 30, 2 46 01 PM Photo Aug 30, 2 46 08 PM

5. Blue and Yellow Combinations

I’m a big fan of how this turned out. Just that transition from yellow to glassy lime green makes me happy.

Photo Aug 30, 2 46 20 PM

Outside: layer of yellow, half celadon crackle, half blueberry
Inside: 1 layer of fireluster, half celadon crackle, half blueberry

Car Shopping with Excel

This topic may be surprising considering that 90% of my blog has been about pottery, but I want to share some thoughts on car shopping. My old car broke down recently and it was time to buy a new one. It was so overwhelming and stressful that I couldn’t sleep when I first started looking (that’s not very characteristic for me).  And literally a day after I bought mine, someone one Facebook asked for car buying advice. I guess i’m not the only one who thinks it’s difficult.

I now have a car that I’m quite pleased with and am about to share what I think the steps are for a fool-proof car shopping experience. I used a spreadsheet with a bar chart to help me narrow down my choices. I happen to think it’s quite clever and will explain it in more detail towards the end (download the spreadsheet).  Ok, here we go!

The Process

1. Determine what you want/need form your vehicle. Without committing to a make or model, make a list of characteristics that are important to you and put them in a spreadsheet . E.g. vehicle type, price, warranty, number of seats, appearance, age of the vehicle, safety rating, mpg, stereo quality, availability of bluetooth,  all wheel drive, etc.

2. Look for what’s available, not what’s theoretically possible. Unless you’re on an unlimited budget and don’t care when you get your car, it’s simply impractical to search all the possible makes, models, and features. You will definitely drive yourself mad. Look up car dealerships in your area on google maps and look through their inventory for things you may be interested in. I narrowed my search by size of the car, age of the car,  and price.

3. Sample.  Pick a few cars that differ on key features that you care about and test drive several. For example, if you aren’t sure if you want a van or an SUV, try driving one of each and see which one you like better. As you test drive, fill in your impressions and other car parameters into your spreadsheet.

4. Gauge price fairness. For each specific car on your spreadsheet, look it up on KBB/TrueCar and see how fair the price is for the features and condition you’re considering.

5. Pick the winner. The spreadsheet should help you narrow down your choices or at the very least organize them and make them easier to compare on a limited set of parameters.

The Clever Spreadsheet

Input

car shopping dataThis green section is where you enter your data. The MPG, price, and year are objective. Look and feel allow you to factor what you enjoy into the calculation. You would rate each car on how nice you think it looks and on how it feels driving. You could always break this down into more parameters.

Calculation

car shopping calculations
This grey and red part transforms the information you entered into the green portion into a comparison and adds all the relative scores into a total score. The comparisons can be arbitrarily simple or complex; just think about what makes sense. Make sure that in your calculation higher score indicates that the car is better. For example, a higher number for MPG is good. A higher number for price may not be good. Let’s look at a couple of formulas:

  1. Looks compares the looks rating of the car to the average Looks score of all the cars
    Excel formula: =[@Looks]/AVERAGE([Looks])
  2. MPG compares the average of City and Highway MPG for each car to the average of City and Highway MPGs of all the cars in your pool.
    Excel formula: =SUM([@[MPG C]]:[@[MPG HW]])/(AVERAGE([MPG C],[MPG HW])*2)
  3. Deal compares sale price to what you found to be reasonable of this car online.
    Excel formula: =[@[Fair Price]]/[@Price]

Chart!

car shopping chart

This is where all the research and test driving pays off.

I sorted the data by Total Score and it’s pretty clear which car is winning. The chart allows you to see why it’s winning. In my example Vehicle 1 is much newer than all the others, has the best warranty, and feels good to drive. It isn’t the best looking car and doesn’t have the highest MPG. By contrast, Vehicle 7 is cheap, looks nice, and has a decent warranty, but feels crappy, and is mediocre on the other parameters.

If you find that in your chart the top car is winning for some parameter that you realize isn’t important to you, you can remove that parameter and see if things look more accurate.  You could also use this information to negotiate your sale.

There you have it.

Copper Disappointment

When the last glaze firing came out I learned the hard way that copper is an unstable element in glaze firings. What this means is that it bubbles and pots come out looking mangled. I was unfortunate enough to not know this and to use several glazes that have copper and totally backfired on me. So next time you’re thinking, “oh, Celadon is so beautiful, so delicate, I’m going to use it on my bowl,” think twice. Check what the hell your glaze is made of and how it might behave. Just because it came in the mail pre-mixed in a nice jar, doesn’t mean it’ll look great.

Exhibit 1 – Carved Bowl with Crackle Celadon

Photo Aug 30, 2 43 44 PM

Carving painted with Peacock and wiped down. Inside: 3 layers of Celadon (up-down, around, up-down) Outside: 3 layers of Crackle Celadon (up-down, around, up-down) Crackle Celadon rim

Not bad, right?  Let’s look at the bottom:

Photo Aug 30, 2 43 56 PM

First of all, thank god it was stilted because otherwise the foot would have definitely fused with the kiln shelf.  Second, you can see those bubbles. They actually popped and have a sharp edge. I would like to think that I did a crappy job of glazing this piece, but I don’t think that’s it because I was actually quite careful with it. Blaming the copper.

Exhibit 2  – Smaller Bowl with Emerald Green

Photo Aug 30, 2 44 09 PM

Inside: Emerald Green; Outside: Pumpkin Spice

This one turned out almost perfect, almost exactly how I wanted it. Except for….

Photo Aug 30, 2 44 24 PM

Part of the inside bubbled just like the Celadon and again I’m pretty sure I didn’t do a crappy job of glazing because the other half of the inside is fine. Plus I applied the glaze with great care and it was very very even.

So yeah, the lesson is not all glaze is made equal and watch out for copper!

The Doughnut – Part Last (3)

I already posted about this doughnut at least twice, which is a lot. This will be the last post. Glazing it was quite a process and it turned out better than I could have dreamed of, so it really deserves its own post.

donut glaze 1

Step 1: 2 coats of Copper Adventurine over the decoration.

donut glaze 2

Step 2: Wax resist over the carved bits of the design.

donut glaze 3

Step 3: double coat of Peacock over the whole thing. Inside is glazed clear (poured in and out).

Photo Sep 02, 7 53 28 PM

Final result – photographed in the light box.

I wish you could see how the copper sparkles in the light, but that doesn’t show in the photo. I’m just in love with this piece. How crazy is it that when I first made it I had no clue what to do with it?