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.

Paper, ink, and process evolution a year later

It has been nearly a year since I have updated this.  I tend to work on projects like this, more at this time of year than at other times.

Recall that I had previously reported fairly good results with sewing pattern paper, cutting up and using ordinary printed sewing patterns.  I also located a source of Burda brand unprinted pattern paper, and found that it gave similar results.

More recently I have been using a paper sold on Amazon as "Medical Pattern Paper" in a 21" x 225' roll for around $12.  This product is sold as a disposable covering for physician's exam tables and spa tables.  It is a machine glazed (MG in paper industry terminology) tissue paper, with one side fairly glossy and the other side merely smooth.  In this, it resembles sewing pattern paper, though it seems a bit different in composition, and of slightly higher basis weight, and is white rather than the straw color of e.g. a Simplicity pattern.  A conversation with the seller of this paper revealed that it is a volume commodity without any real detailed specification or rigorous consistency from lot to lot.  I have two different rolls from two different sellers, and each shows differences in behavior.

[Update]  On the Web I located a more recent US application for pottery tissue: applying wax resist for metal etching (typically for texturing of tool and mold surfaces).  This application has lapsed in favor of laser patterning, but the company referred me to their former paper supplier (a distributor in Stoke-on-Trent, UK).  The gentleman who answered at the paper supplier said that they no longer carried the material, given that they had seen no demand for some time.  As stated by another source, he confirmed that the material was either identical or similar to cigarette rolling paper, and had been supplied by Bolloré.  There might have been a prospect of getting some if I wanted an industrial lot of around six master rolls.  My understanding is that a master roll typically amounts to around 2000 pounds.  Ha ha ha.

As an adventure, I found a smoke shop that was open on Christmas day, and bought a packet of the largest rolling papers they had in stock: Elements king size (110 x 55 mm).  These are described as being a rice paper, manufactured by HBI in Alcoy, Spain.  When soaped as described below, these have given some of the best transfers so far, though the size is limited.

Following a sketchy account in an old book as related in a previous post, I have been sizing this paper with a soap solution, in either one or two coats, brushed on and allowed to air dry.  (I have abandoned the practice of using dry soap as a crayon on the paper.)  As previously noted, this is a simple uncolored and unscented bar soap locally made by a craft soap company (Swan Haven Soap, Petaluma, California) which they describe as being made from vegetable oils saponified with sodium hydroxide.

Following (or perhaps misinterpreting) accounts of current practice at perhaps the last remaining commercial pottery (Burleigh) using paper transfer, I have incorporated pine tar into my ink.  This appears to work quite well as a tackifier.

The specific pine tar is one that was sold by Rawlings for improving hand grip on baseball bats.  I believe that Rawlings may have discontinued this specific product.  It still is available from at least one online source, sold as Rawlings Genuine Pine Tar, in a metal can with an applicator brush in the cap (like you might see for contact cement).  This material is black and quite thick.

I am not yet measuring (difficult to handle and weigh viscous liquids), but I am guessing that I use around 4 parts of #8 burnt plate oil (Graphic Chemical) to 1 part pine tar, mixed on a hot plate.  Pigment/frit mixture is then added until the ink looks and feels close to something that has worked in the past.

I ink and wipe the plate hot, reheat it, and take the impression while hot.  Layering for the impression: bed of 1/16" polycarbonate, Solarplate, soaped/dried tissue, sheet of lightly dampened newsprint, sheet of dry newsprint, thin piece of craft store synthetic felt, 1/4" reinforced rubber etching blanket.  This all gets rolled through an ordinary pasta machine of the type sold for polymer clay craft (modified to remove curved plates and rods below the rollers).

Immediately after impression, I carefully pull the tissue from the plate.  From time to time I try reheating before pulling, but the transfer recently has tended to be better if I do not reheat.

More recently my emphasis has been upon transfer to ordinary glazed ceramic commercial bathroom tile, as a cheap and convenient substitute model for what I am actually trying to do.  Again following an account in an old book that mentioned "a fine varnish", I prepare the glazed surface with a very thin coat of #7 or #8 burnt plate oil that I then allow to stand for a few days (or better: weeks).  For quicker work I cheat by using Winsor & Newton dammar varnish, which has a benzol/turpentine solvent and dries more quickly than waiting for linseed to dry on its own.

I cut the printed design from the paper, place it on the varnished surface, then burnish it down with the round end of a wooden paint brush.  Sometimes I allow this to stand a while, and sometimes not.  I then place it into cool water and agitate.  If I have done the soap and ink correctly, the paper will float away after a couple of minutes, leaving nearly all of its ink on the ware and only a faint remaining image on the paper.

With a varnished ware and pine tar in the ink, I am getting fairly good adhesion of ink to ware, and fairly good release of the paper.  I am still having difficulty in getting a consistent transfer of ink from plate to paper, and have trouble with plate tone (failure to complete wipe ink from what ought to be uninked areas of the image), especially with the staining power of cobalt blue.

I then fire at 1900F, holding for 25 minutes.  Afterwards, I might apply a clear glaze and fire again.  This seems to work well with cobalt blue pigment, but the clear glaze seems to mostly annihilate images from my brown pigment (Gamblin Burnt Umber, which on second glance appears to contain manganese as well as iron).

One worrying development is that Solarplate have reportedly changed the composition of their product.  I have not yet tried the new plates, but I believe that they are reported to have a thinner coating.  If so, they might work less well for this application, where we want to transfer more generous amounts of ink than are necessary for conventional printmaking.

Crucial elements:

1. Soap sizing of the transfer paper: just enough, and more is not better.
2. Pine tar as an ink tackifier.
3. Varnish of fired wares before transfer, to greatly aid ink adhesion.
4. The right paper: medical pattern paper is good, cigarette paper is better but size-limited.
5. Not-yet-characterized interaction between intaglio feature size/structure and ink characteristics.

Sizing for paper

I received a copy of Rudolf Hainbach's Pottery Decorating, 2nd English edition, 1924.  Various works have disparate descriptions of the soap sizing and its application to the tissue.  The sizing is typically referred to as a solution or a thin solution of soap in water.  One source specifically says potash soap.

Hainbach gives more detail: "... the color does not come into direct contact with the paper, but rests on the layer of soap."

"The soap mass for this purpose is prepared by cutting good white curd soap into fine shreds, and boiling these with pure water in a vessel until fully dissolved, so as to form an opalescent but transparent liquid that is viscid when warm, and in this condition will flow from the spatula."

He also says that after transfer, the ware is put into water  at 30-40°C, swelling the paper and dissolving the soap layer, "... destroying the connection between the paper and the color."

This argues for a contiguous and not too thin layer of soap.  I prepared some soap solution, more concentrated than described above, and squeegeed it onto several types of tissue.  I will try printing some of these tomorrow, also using a modified ink.  This ink contains some gum dammar, that being the most readily available natural resin (the art store has it with encaustic paints).  This seems to add tack.  I am eager to try it after the tissues dry.

The soap that I am using is a locally made unscented vegetable oil bar soap.  Soaps of the original time almost certainly were made from animal fats.  My grandmother made an eye stinging but very effective soap from saved bacon grease and lye.

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I was able to try printing with the soap sizing mentioned above.  Ink take-up on the paper seemed reasonably good, but the fired image was too faint.  Most likely I needed more oxide proportion relative to frit.

The ink formulation that I was testing here also contained gum dammar, which I had hoped might act as a tackifier.  The jury is out on that.  Some Burgundy pitch (typically a spruce resin product, sold for optical polishing) arrived today, and I will be trying that as well.  The gum dammar seemed to make the ink more fluid when heated, but a bit tackier when cool than with burnt plate oil alone.

The heavier soap sizing, and the use of warm water per Hainbach, gave promising results with respect to water lift-off of the tissue from the ware.  Both sewing pattern tissue and cicada wing xuan paper floated free with just a bit of agitation, and no pulling required except to get the paper out of the way and keep it from settling back down onto the ware.  Sewing pattern tissue seemed to give the better transfer, but cicada wing floated away more readily.

Promising new paper

A correspondent on a ceramics discussion site recommended "cicada wing" xuan (shuen) paper as used for traditional Chinese brush painting.  Blue Heron Arts sent some amazingly quickly.

It has poor wet strength but perhaps adequate.  It is said to be sized, maybe with glue and alum.  It has some of what appear to tiny shiny mica flakes, but these are sparse and appear not to cause trouble.

Before making the impression, I size one side of the paper by rubbing bar soap on it, then mist the other side very lightly with water, then print on the soaped side.  The soap seems to make the paper more supple even before misting.  Ink take up seems very good, and unlike tissues, the ink does not push much through voids to the back side and backing sheet (dampened newsprint).

Unlike sewing pattern paper, it tends to disintegrate rather than float off intact when soaked after transfer.  This is a bit annoying, but it might not be a big problem.

Japanese pre-printed transfer tissue results

Here are results from a test of the Japanese pre-printed transfers.  The left piece was transferred onto a fully fired coupon; the surface was first prepared with gum arabic and dried.  The right piece was transferred onto a bisque fired (1925F, 25 min.) coupon; the surface was just brushed with water first.

The bisque fired piece took up the color remarkably well.  The poor lighting and focus of the photograph do not do the best job of rendering the subjective appearance of the right hand piece, though they do a good job of showing the flaws in the left hand transfer.

These pieces were fired to 2225F, held for 25 min.  They were then coated with a little clear glaze and fired at 1925F for 25 min. (alongside a bisque firing of some other pieces destined for later tests).

I subsequently did more transfers to a few bisque fired buttons and test coupons.  When I put these into a hot kiln (around 800F after a previous firing), I noticed that the entire surface of each piece rapidly turned brown.  This suggests that the tissue paper is uniformly coated with some sort of organic sizing material before it is inked.  The paper itself is entirely peeled off before firing, so the browning is from a soluble coating that has transferred alongside the underglaze image, not from the paper itself.

The material appears to be sophisticated in its refinement, though the transfer characteristics of various designs do not seem to be especially uniform.  I suspect that the material does not have an especially long shelf life, and that older material either gives irremediably poorer transfer performance, or perhaps needs more water and a longer stay before peeling.

Commercial tissue transfers (from Japan)

Today I received from Australia, several sheets of commercially produced transfer tissue from Japan: both pre-printed patterns and blank paper.

I had been working under the assumption that transfer tissue should have fairly high wet strength.  This turns out not to be the case for this paper.  Its wet strength appears to be perhaps not as poor as ordinary wrapping or craft store tissue, but not much better.  One difference is that one surface of this paper is smoother: calendered or sized.  It has that in common with sewing pattern paper.

Meanwhile, a roll of wet strength tissue arrived today from Talas.  It is very strong when wet: at least as strong as a teabag.  After comparing it to other abaca tissues that have arrived recently, I suspect that it will have fairly poor take-up of ink from intaglio printing.  So far, nothing beats sewing pattern paper.

The pre-printed patterns use a water soluble formulation, not an oil.  Online materials suggest that one can screen print onto this paper with (presumably ordinary) underglaze.  My results with screen printing of anything, glaze or not, have been abysmal.  I probably ought to give it another try.

This tissue seems very unlikely to survive intaglio printing.

Piecing together some other discussion found online, it looks like CBM cellulose might be a useful medium for formulating water soluble glaze ink.  I have experimented with CBM as a sizing for tissue, but had better results with unsized paper.  I should try making some ink with it.

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Later on...

In tried transfers onto bisque fired and fully fired test coupons.  The results are promising but not immediately consistent.  I had excpected the bisqued pieces to give better results, but the transfer seems less substantial than it ought to be.  I suspect that the ware is too absorbent and pulls the water out of the transfer before the ink is able to soften and bind.  The most promising result was on a fully fired piece.  I sized the surface with gum arabic before applying and moistening the transfer.  I then allowed the transfer to dry at a floor vent from the furnace.  Next I brushed a little water onto the back of the paper then peeled before the water had too much chance to go deeper into the ink.  This gave a fairly good transfer, though with some holes in the ink.  It is firing now, to 2225F.

Decorating fired wares

I had been working under the assumption that transfer printing was done onto bisque fired wares.  There are good reasons for this not to have been the case for calico buttons.  The buttons themselves might have been produced at one location, then transported to another location for printing; my bisqued tests are too fragile to invite being dumped into bags and loaded onto horse carts.  If the same button was sold both in both plain and decorated forms, it makes especially good sense for the decoration to have been applied to fully fired wares.

My experiments with decorating fully fired wares had been dismal failures.  Ink adhesion is very poor; most of the ink comes off with the tissue.

Recently located, however, is a book by C.F. Binns: The Story of the Potter  published in 1901.  Beginning on page 217 (the book is readily available in scanned copies online), Binns gives a popularized but detailed account of the transfer printing process as used for household pottery.

Binns on transfer printing 

He notes that "a fine varnish" was applied to the wares to promote adhesion of the ink.  Taking that hint, I took a few fully fired test coupons from early body experiments, heated them, and applied a thin coating of #8 burnt plate oil.  The results are somewhat promising.  I have been able to obtain better ink adhesion, but I have increased difficulty in removing the tissue.

Another reference (specifics not remembered) suggests that a potassium soap was used in the process.  Binns states that the transfer paper is prepared with a soap and water solution before the impression is made.  Potassium soap stands to reason here, because potassium soaps tend to be liquids, whereas sodium soaps tend to be solids.

A readily available potassium liquid soap is Dr. Bronner's.  I am trying the Baby Mild (no fragrance) type; most of the fragrances contain terpenes that seem likely to act as solvents for the oil medium.  (I use one of the household citrus-based cleaners to clean ink off plates, hands, and utensils.)

I need to experiment with soap concentration to see if there might be one that allows the ink to adhere well enough to the tissue while making the impression, yet promotes release of the tissue from the ink/varnish/body when soaked after transfer.

Also, I have a few other types of tissue paper on order.  Some are sold for conservation and book repair, and claim to have good wet strength.  Thinking a bit about wet strength, I tried printing on tea bag paper: ink transfer was disappointing to the point of being useless, possibly due to porosity, though the wet strength was much better than for sewing pattern tissue.