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.

---

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.