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Thermochromic pigment tests

June 21, 2013

I painted a few swatches using the thermochromic pigment with a transparent acrylic medium. It doesn’t change from simple body heat, at least not for quite some time (I wore it around the house next to my body for a while).

In this video, I’ve just blown on it, and while it disappears quickly (insert jokes about me being full of hot air), it also reappears quickly, starting before I can even put it down to take the video. Then you’ll see that you have to rub it pretty vigorously to create enough heat for the change:

But then I plugged in the heater I intend to use and tried that. The change was a little slower than expected–I think I need a layer of fabric that heats up quickly. Any thoughts on what absorbs heat well? Something dark and…? I’m undecided on whether natural fibers or something manmade would work better! Might have to do a few experiments with that.

But on top of that, the reverting back doesn’t happen nearly as fast, even once I remove it from the heat source. Maybe I’ll just have to stand near an air conditioning vent? I unplugged the heater near the beginning of this video:


Wires, wires, everywhere, and not a color change

June 18, 2013

Goal: Use thermochromic pigment in a costume to make it change colors. More specifically, an entire corset.

I assume this project is the result of a deep and never fulfilled desire for a Hypercolor shirt, because that’s essentially what we’re talking about here. But pressing a hand against it won’t do. I need to heat the whole thing to at least 93° F, which means something powered.

It turns out heating an entire corset that warm is no cheap-and-easy task. There is such a thing as a heated vest, but they’re not cheap, and they generally plug into a motorcycle’s 12v socket because that’s who they’re meant to warm. I looked at a lot of other options from conductive thread to stainless steel ribbon to carbon tape to having someone follow me around with a cordless hair dryer. OK, I didn’t consider the last one for too long, but it turns out those aren’t easy to come by either. The easiest solution seemed like it would be something USB-powered that plugged into my iCarrier power brick, but USB-powered heating things are very small, and 5v is not very much. I was at a dead end.

Then I remembered that I have an old seat warmer for the car that plugs into that aforementioned 12v socket. I talked to awesome friends like Tom and Eco, not to mention Chris Gammell, who has sent me lengthy emails about electricity even though I don’t know him just because at one point somewhere between my exhaustive USB hunt and carbon tape adventures, I ran out of Googling ideas and tweeted, “I need a nice electrical engineer friend.” And I concluded that this turkey was just the gobble gobble I needed. (Guess what I had for dinner?) This thing is pretty much perfect–it’s a maze of wires that heat up and cover an area roughly my body size, and it already has low/high/off switches in its cord, which I figure I can hide in a belt or something:

(This is where I’ll show you a picture eventually, but my phone is so dead it won’t stay on long enough to upload a picture anywhere.)

I got this AA battery holder (because 8 AA x 1.5v = 12v) and one of these female car charger bits. (Say what you will about Radio Shack, but it’s across the street from my house, and the guy was totally into making this work.) The battery holder has the 9v-style connector snaps on it, so I got the other half of that with wires out of my handy-dandy box-o-bits.

Thus the connection is:

Seat warmer power cord > female car charger dangly bit (technical terms!) > 9v snap wires > battery pack

I tested what was coming out of the snap connector wires, and it was solidly 12v. Hooray, I thought. It works! And then the electricity proved me wrong. I plugged it all in, and that bad boy did not heat. I gave it several minutes, and at best it warmed to 77°. I’m near an a/c vent, so it started around 72-74°. That’s not going to get me to 93°. I took it out to the car and plugged it in there to make sure I didn’t break something when I cut it apart, and within a minute, it was over 100°, so I know it’s still working.

Here are my readings:

  • Without the female DC connector attached, the bare wires off the 9v snaps read 12v.
  • When I attach them to the connector and test the connections (being careful not to touch the wires instead), it’s 10.6v.
  • When I plug in the seat warmer and turn it on, that measurement on the connections drops to to 6.3v. And it doesn’t heat.

Suggestions? What’s going wrong?


Thanks to the lovely people of FB and Twitter, I believe I’ve concluded that the resistance of the heater is around 6-8 Ω. Thanks to this handy-dandy Ohm’s law calculator doing the math for me, I see I should be aiming for around 1.7 A and around 20 W. Problem not solved quite yet, but information added. 🙂

How I spent 2012

January 11, 2013

Some people print hundreds of pictures and weird scissors and pretty paper and make beautiful things called “scrapbooks.” I try to get all my pictures downloaded from the SD card within the same year they were taken.

Last year I made a wordy graphic (inspired by Nicholas Feltron’s annual reports) about how I’d spent 2011. This year I went with more pictures. And it’s longer. It’s a lazy gal’s scrapbook. And kinda messy, just like me.

Click the image to embiggen. It’s big.


Trapped by my screens

October 3, 2012

Today was the day I realized I forgot how not to look at a screen. Then today was the day I decided it was time to remember.

I could be a lot worse. I remember when someone asked with incredulity why I don’t have my smartphone by the bed. That doesn’t need to be the last thing I see at night and first in the morning. The rest of the day is bad enough.

I spend hours reading email, writing blog posts, and keeping up with communities in IRC channels. Twitter, Facebook, YouTube. I often walk back from my daughter’s bus stop reading something on my phone. When I take a break, I might read a book on my Kindle or play a video game on the Playstation. Screen after screen after screen, non-stop.

Upon realizing this, I decided to take a break. Look at something else. I decided to bake gingerbread. Did I look up a recipe in the shelves of cookbooks I own? Nope. I searched for it online and referred to it on a tablet in the kitchen. Screen-escape fail.

I tried to think of what else I enjoy that doesn’t require a screen. Sewing! I’ve been putting off a corduroy jacket behind other priorities. But then I realized that I’d forgotten the trick to making welt pockets, and I needed to look it up. Back to the computer.

Having run out of ideas, I guess I’ll make lunch instead. Surely I can handle that without looking at a screen. Or maybe I should just write a quick blog post about it first…

Ravenna status: Thirteen days and counting

August 15, 2012

There was vacation, and there’s always work, and there’s actually working on the costume… so I haven’t posted much progress lately. And all the photos are taken late at night with my cameraphone, so there’s that. But here’s how it’s going.

The skirt portion has been a special little beast. Back in July I posted about how I was working on the skirt hook findings, which were originally sourced in Turkey, and, well, I’m not in Turkey. I wrote that Sculpey would be fine since they were just decorative and didn’t have to actually hold the skirt’s weight. Then a week ago, I was looking at the pictures for the eleventy-billionth time and realized they do. The skirt is separate and attached to the bodice by those pieces. My mister suggested resin, and my superhero-pal-in-Dragon*Con-crime Neal helped me with his resin experience to start casting them. Only 20 to go! Then drilling, painting…

But back to the skirt itself–you ever start doing something, then think, ooh, I know a quicker way, all the while knowing you should do it the right way instead? Yeah, that. I started out putting the skirt together with the piping between the layers, all in one pass, like this:


The right way would have been to make the piping, then insert it into the seams. But I just knew I could shave off some time doing it all at once. When I started ironing them flat, I realized just how inconsistent the width of the piping was. I’m not a perfectionist. I’m usually a close-enoughist. But this time I knew what I had to do. I took apart the entire skirt, all 24 panels, all 184 feet of stitching, and I started over. I made the piping first, then put it in.

If you figure I’d already done some of them 2, 3, or even 4 times in places trying to even it out to fix my cheat, that’s about a tenth of a mile of seams.

I’ve put a few of them together. They still need a lot of ironing, but you can see it will be the skirt!

Then I started worrying that the points would lose their pointiness after travelling to Atlanta and hanging in a closet for a while. So I started thinking about stitching in the ditch between the piping and the panel. It’s a slow-going process to keep it from being a disaster on the second side, but I think it’ll work.

Finally, the bodice. I’ve gotten most of the leather piping sewn to it. Next up, gold beads and sequins.

Thirteen days to go!

Oatmeal biscuits

August 9, 2012

I’ve made a lot of biscuits, but oatmeal biscuits are a new one on me. And that’s exactly what The Flying Biscuit sent out a recipe for in their daily email today.

2 cups rolled oats
2 cups whole wheat flour
1 cup butter cut into pieces
1/2 cup packed dk brown sugar
1 3/4 tsp double-acting baking powder
1 1/2 tsp salt
1/2 cup whole milk

– Chop oats in food processor
– Pulse flour, butter, sugar, baking powder and salt into coarse meal
– Add milk to make sticky dough, then add oats and knead until mixed
– Make two 6×3 inch rectangles and refrigerate until firm
– Cut loaves into 24 1/2″ thick slices and bake at 375 for 20 minutes

Together! Ravenna’s bodice

July 25, 2012


I kept meaning to post photos of some version of the muslin for this bodice, but I never took a picture of it, and now it’s in a dozen pieces. I’m no expert pattern maker, and this wasn’t an easy one. But the bodice is together! I haven’t ironed it yet, but I did serge the edges so it’ll hold together long enough to get the hand embroidery on in the center front.



I’m terrible at corners. V-necks, godets, things like that. So I picked a dress full of them. Genius. Practice by fire. I’m not too proud of the way the v-shaped insets fit in the bodice–I had to make some darts at the bottom to make it work out. But I am rather pleased with these two L-shaped corners on either side:




Look how smooth! And it’s not even ironed yet! 

I also got most of the necklace made except for the pendant. I’m still hunting for the right pieces for the earrings. Just a few weeks to go!