Real pottery tissue and rethinking

First, I was able to locate a product that is sold directly as pottery tissue, from Potclays Ltd., Stoke-on-Trent.  They are the only supplier that I have been able to locate.  The material itself is not terribly expensive, but shipping to the US (they used DHL) was around 3x as much as the material.  It comes in a roll (cut to length) and is around 30 cm wide.  I will venture a guess from available photos, that this is the same paper that the Burleigh pottery still uses for transfer printing from their cylinder presses.

I will venture a further guess that it was manufactured by Bolloré Thin Papers.  It is about the same weight as cigarette papers.  It bears no watermark, but does carry an impression of the papermaking machine's screen.  Neither side appears to be machine glazed.  The color is very slightly off-white, and it is not bright.  My guess is that, unlike cigarette paper for factory-made cigarettes, it contains no opacifiers, ash modifiers, or burning modifiers.  By comparison to roll-your-own paper, it is less slick and lacks a watermark (brand loyalty reinforcement is crucial in the roll-your-own industry, and one brand claims that their watermark contributes to even-burning).

This paper has generally superior performance.  In fact, it arguably performs better in wash-off without being soaped, than it does with soap.  It takes up the ink quite well.  It also performs well with only #8 burnt plate oil as the ink vehicle, no pine tar.  In wash-off the paper appears to swell somewhat, then usually releases with only some agitation.  Very little ink remains on the paper.

Given that soap and pine tar can be factored out of the equation, the next question for my specific objective is to see whether wash-off can be eliminated, with the paper being burned off in firing.  The answer to this is "maybe."  Past attempts with full rate to 1900 F, plunging the wares into the kiln at 1400 F, pre-baking in the kitchen oven, have all been terrible.  The paper ignites suddenly and spreads the ink around in clumps and swirls.

Taking hints from a decal hardening-on firing schedule mentioned somewhere online, and improvising a bit, I tried the following:

1. Full rate from room temperature to 438 F, hold 15 minutes.
2. Full rate to 650 F, no nold.
3. 100 F / hour to 800 F, no hold.
4. Full rate to 1900 F, hold 20 minutes.

Step 1 is mine: take the temperature to just short of typical paper ignition temperature and hold a little while.

Step 2 is taken from the decal schedule.

Step 3 is taken from the decal schedule, but I use double their suggested rate of increase.

Step 4 full-rate is taken from the decal schedule, but the endpoint and hold times are my usual of 1900 F and 20 minutes.

The first firing with this schedule looked fairly promising.  Not as good as wash-off, but promising.