After the rain…

That didn’t take long! The situation I was trying to simulate is one where the painted leather is kept wet for a period of time. I had this happen at Easter 2009 where we hosted a 17th century tavern that ran for four days. By the end, all the leather drinkware was soaked and the paint was just starting to bleed.

After the rain
As before, oil at the top, then gouache, then acrylic. Modern dye to the left, iron black to the right

I must admit, early Summer rain in Sydney is somewhat akin to being shot-blasted, but it has accelerated the testing nicely. The oil on modern dye, which had already started to chip, suffered quite badly from this treatment. The gouache on iron black mostly washed off, on the modern dye it stood up a little better and could have been rescued by bring it in earlier and gently drying it. As you would expect, the acrylics are largely unaffected, as is the oil paint on iron black.

Remember, all samples are from the same piece of hide, and all have a coat of varnish and a heavy coat of beeswax over the paint.

Once they’ve dried out, I’ll simulate washing up.

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Remember these?

Paint tests 2
From top down, oil paint, gouache, acrylic, left samples are modern dyes, right are iron black.

I’ve had the samples sitting for about six months, just to make sure the paints were really dry. They were dusted off and given a light coat of beeswax to finish sealing them, as I do with the painted drinkware. So far, they’ve had an easy life.

As expected, the acrylic stuck to both samples. What I wasn’t ready for was the way the oil paint seemed to be just sitting on the surface on the modern dyed piece. It smudged when I hit it with the wax. The gouache is having some problems the other way around. In that case, the modern one is fine but the iron black sample seems to have thinned the coating somehow. Possibly it’s reacting with the paint.

I’ll keep on with the tests as planned. Tomorrow might be a good time to leave them out in the rain.

Paint tests, part 1

Late last year I discussed painting leather and promised to do some testing to see if oils or gouaches weathered better. The implication was that the originals could have been done with either, again mainly me trying to justify not waiting a week for each coat of paint to dry.

I’ve just started painting and  have my answer already.

I’ll briefly recap first. Six samples of the same 4mm harness butt were stamped and dyed, three with a modern water based black dye and the other three with a home made iron-based dye. One modern and one traditional sample were then painted with each of oil paint, gouache and acrylic. The stamped area was used to see if there’s a difference between compressed areas and paint on top of the leather. The number “1” was used as it had a  number of sharp points where failure could occur.

Paint tests

The samples and paints. The gum arabic is for diluting the gouache, the gum turpentine (out of frame) for the oil.

The gouache flowed beautifully on the modern dye, as did the oil on both samples. The acrylics had a really hard time covering the black base on both samples. The acrylic will need a minimum of two, and possibly three coats to cover as well as the others. The problem with both the water based paints is that the iron dye makes the leather hydrophobic. The water-based paints bead on this surface, leading to rough edges and poor adhesion.

Paint tests

First coat finished, I’ll tidy the edges on the next coat. From the top down are acrylic, gouache and oil, the iron dye is on the left. The beading can clearly be seen on the 1 in the centre left sample.

The moral of the story is that if you are using an iron dye, you have to use oil based paints.

So, what am I doing different?

Things have been a bit quiet here lately, mainly due to a new job but also a dose of shingles left we with no energy for anything.

I’m on the mend and have finally got around to dyeing the samples for the paint tests. I’d prepared the dye about the first week in January, by pouring about 125ml of cider vinegar in a container and then adding enough 0000 steel wool to just be covered by the liquid. I agitated it every couple of days and two weeks later when the steel wool had dissolved, added as much again. It has sat that way for the past three weeks and now is a grimy brown liquid with residual grit sitting at the bottom.

I’d done some reading and everyone seemed to complain that the best one could expect from this sort of dye was a darkish grey that would darken on application of tallow or wax, so I was prepared for patchy results. I did a single dip for each of three pieces of the same harness butt I use for my blackjacks and leather bottels. As I lifted each one out, it was a pale grey that darkened almost immediately to a deep grey, deepening within minutes to an even, deep black. So black, I had to label the samples so I could tell them from the samples done with modern spirit dye.

Iron dyed veg-tanned leather samples. This is 30 seconds after the dye dip.

Just in case it was a particularly high-tannin leather, I also tried samples of carving leather, newly tanned calf leather and a piece of heat-sealed goat skin. All but the goat are jet black, it has gone a pleasant pale silver.

So what have I done differently, or what did I do right? Did ignoring the mix for three weeks contribute to this success?

Black jacks, part 2

So you want to make a black jack… You’ll neet to get the right materials, some equipment and the usual leather working tools. I’ll briefly touch on each of these before going on to discuss manufacture techniques. If you want to open part 1 in another window, you can cross-check the summary of requirements at the bottom to keep me honest.

Materials

I generally make my jacks and bottels from harness butt. It’s about 3.6 to 5mm thick, has a smooth matte surface and moulds exceptionally well. You need a thickish leather that moulds well and hasn’t been heat-treated.

You’ll need some dye, black is traditional. I’ve used a spirit based leather dye in the past, but am considering an iron-based dye for next time. This dye is chemically very similar to the ink Baker mentions, you could use ink, but avoid India inks as they are carbon in suspension and will shed black over everything.

Linen is the best thread to use, being accurate and strong. I have a 23km reel of fine thread I got on e-Bay from a mill that was closing down for not very much money. It is very fine, so I have to use six-ply on jacks. No, you can’t have some, get your own. Make sure you get enough, you’ll probably need to make two-ply if you use the thread that comes on cards in haberdasher or on reels from leather stores. You do that by cutting two equal lengths of thread, give them a moderate coat of wax and then roll them in one direction until they become a single thread. If the thread kinks or forms loops, you’re rolling them too tightly.

Which brings me on to the next item – wax. You can use pure beeswax quite happily, but if you are feeling adventurous, try coad, a 2:1 to 4:1 mixture of pitch and beeswax. The proportions are best worked out by experimentation, beeswax here is fairly soft for most of the year (and occasionally a sad-looking puddle) so I need more pitch. In Europe and North America, more beeswax may be beneficial. Have a look at this thread, but don’t get scared away by the technical detail some of the correspondents go in to. Plain wax works fine.

Equipment

Most of the equipment I use is in this photo below. The only thing missing is a short length of 90mm PVC storm water pipe that takes the place of the outer ring in Baker’s figure 72. If you have a tame blacksmith, by all means get a pair of iron rings made instead and earn bonus points for being hard-core.

Almost everything you need to make a jack.

Clockwise from the front left corner: there’s the wooden disk, 80mm diameter, 20mm thick that I use with the drain pipe as a substitute for Mr Baker’s paired iron rings; the hinged stretching frame, made from 100 x 50mm radiata pine  recovered from an old kitchen cabinet (the nine screws in the bottom right corner reinforce a split that runs along the grain); the mould/core turned up for me by a friendly woodturner from an old kauri pine table leg at the cost of approximately 3 beers and; the removable piece for moulding the spout made from offcuts of radiata.

Showing the way the frame boards are cut to match the mould core. ‘Scuse fingers.

Tools

You’ll need the usual implements of terror: harness needles or pig bristles if you can get them; a strong, sharp awl as some places are nearly 20mm thick; a sharp knife with a good point for cutting out the pattern and the handle – I use a Stanley knife/box cutter because I don’t yet have a half-moon knife and; a butter knife or embossing tool if you are going to do the parallel lines around the spout. You may also want some stamps if you are doing any stamped decoration.

Construction

Cutting the leather

Cut the requisite two pieces of leather. The main body piece should rectangular with the short side approximate the desired height of the finished jack and the long side equal to the circumference at the smallest diameter of the mould (near the top on mine) plus the width of the handle on each side, plus a bit extra for banging nails into. The long axis should lie across the hide to gain maximum advantage from the natural stretch of the leather. The other piece is roughly circular, the diameter of the wooden disk, plus at least twice the height. A bit more doesn’t hurt as it will be trimmed to shape later. I tend to hack these out of the odd sticky-out bits near the edge of the hide.

I didn’t do any photos of the cut-out bits, you know what a rectangle of leather looks like and should be able to infer from the later photos anyway.

Forming the base

Soak the leather, then place the wooden disk against the skin side in approximately the middle of the piece and then push the entire assembly into the end of the bit of drain pipe flesh side first. The pipe should compress the leather against the wooden disk, and if the sizes are right, result in a nice sharp transition. This is much the same method as used to form the ends of costrels, but a little easier as you are using a commercially available outer mould. Set aside to dry, the time will vary depending on where you live. If you live somewhere really cold or damp, put it in the oven at it’s lowest temperature for a couple of hours but take care it never approaches 70° C / 155° F as you don’t want the leather to harden. Again, no photos so have a look at the costrel end ones and imagine something similar… but round.

Forming the body

Watch carefully. Because there is some space at the top and bottom, draw some lines on the frame to help align the leather. Wet the leather and nail it in position on the back edge of the frame. This stops the leather stretching unevenly around the nails. If it’s too loose, you can always pry it off and re-nail it a little tighter as I had to on my first one.

The leather nailed in place and tightened around the former. I left the leather far too long on this first one, the second one was done with a shorter rectangle. You can see the crack in the frame opening up.

Then stuff the core in the middle and clamp, the threaded rods help the frame keep in alignment when tightening, but are probably unnecessary. Once that’s clamped properly and assumed the correct shape, squeeze the spout bit in. I found doing the two parallel lines around the spout with the back of the obligatory butter knife really worked the leather tightly in around the spout. Do any other tooling or stamping at this point.

The spout piece in place.

Once dry, remove loosen the bolts or unclamp and remove the nails and feel smug.

Dried, pried off and feeling smug.

How are we going against Baker’s list? I’ve used two pieces of leather, formed it on a wooden core with a removable spout piece and shaped the base using two iron ring substitutes. We did a little embossing around the spout while still on the core, although its a bit awkward working around the frame. So far so good.

Trimming

Pop the base out of the pipe, keeping the bit of wood inside. Trim the base to between 15 and 20mm high.

Take the body and cut out the handle, cut a couple of handle copies out of the waste. This one has a mid-17th century handle shape consistent with the double embossed lines around the spout.

All the bits cut out. The reinforcing pieces are cut from the waste. I suspect this is the stage Baker based his schematic on.

I’m cheating again. The photo below is from my second attempt at making a jack this way because my first was way too long and had more waste than I was aiming for. Let’s have a quick list check again: started with a single larger piece for the body, cut to shape and cut the reinforcing bits from the waste.

This is the waste from my second attempt. I doubt I could do much better starting from a rectangle.

You’ll need a welt the same height as the base with the length the same as the circumference as the base. I made mine up from several pieces cut from the bigger bits of scrap, beveling the ends so a single stitch could hold both in place. You could also use a separate strip, but I’m trying to stay within the confines of Mr Baker’s list. Now it’s time to dye all the parts (I’ve already done the base in the photo above) and let them dry.

Assembly

There’s not much to tell here, do the back seam first, followed by the seam that runs along the outside of the handle. The closer the back seam is to the crease between the handle and body, the stronger and easier to waterproof the jack will be. Then sew around the inside of the handle, and once done, cut out the centre of the handle.

Back seams done, handle cut and the base sewn in. I haven’t re-dyed the cut edges yet.

Pay close attention to the stitch spacing, and make sure the stitches are perpendicular to the surface. You also need to make sure they are in a straight line on both sides of the handle or it will look ugly and can lead to stitches being cut when you cut out the eye of the handle.

View from underneath showing base, welt and the intersection with the handle reinforcing parts.

Force in the base and welt and secure with two rows of stitching. That’s pretty much it. Do any trimming you need to tidy the edges, then re-dye. Neaten the cut edges by dampening and rubbing with a plastic slicker or piece of bone. I like using lamb bones as they bring the edge to a high gloss.

I usually do the painting at this point, but you can wait until after pitching if you’re worried that the heat will affect the paint.

Sealing

I have a hoard of black brewers’ pitch that I use for bombards and jacks.  I generally cover the outside with kitchen foil so any drops of pitch don’t mar the outside or stop the adhesion of the paint. Heat the pitch, pour in, slosh about so everything is covered and pour back in to the pitch pot again. The pitch should be hot enough to be runny, but not smoking. You can build up a good even coating with multiple coats if the first seems too thin. If blisters or runs are causing you problems, a couple of hours back in the oven at 60° C should help even out the surface although it will make everything slump towards the base slightly. Turn the oven off and allow to cool before removing the jack so you don’t craze the pitch. This step simulates the technique of hanging jacks in the smoke of a fire that Waterer talks about in Leather in Life Art and Industry.

Some people prefer to mix wax with the pitch to make it flow or to extend it. That doesn’t work for me as the pitch is soft enough as it is. Others use Envirotex or other food grade epoxy as some jurisdictions consider pitch to be a carcinogen. I’ll leave it up to you, but I think the risk is acceptably low as I use these less than once per month and am exposed to other carcinogens such as plasticisers on a far more regular basis.

Finishing

Varnish over any painting and then give the entire beast a good rub down with a wax furniture polish (or sealing wax dissolved in alcohol).

Summary

That more or less concludes the making of the jack within Mr Baker’s constraints. We’ve formed the base from a single piece of leather, worked over a round former. The body was cut as a single piece of leather, and after moulding around a wooden core with a removable spout piece, the waste around the handle was cut off and made into the reinforcing pieces. Embossing took place while still on the block and the handle wasn’t finished until after the stitching was complete.

I feel I have achieved all the self-imposed requirements based on Baker. My only additional step to those in the book was using a stretching frame. Other more skilled artisans than I may be able to mould a jack around a core with their bare hands, but I find it essential to compensate for my shortcomings and helpful in an early modern period style of mass-production.

I like to kid myself that if my methods approach the historical methods used to do something, my mistakes will resemble their mistakes. Here’s a picture of what uneven stitch tension did to one of my jacks, and to a seventeenth century one in the MoL collection.

This is what uneven tension did for me.

Similar problems in the 17th century. Sorry about the flash. For more information, see the MoL record.

Here’s two I prepared earlier. The one on the right is my first attempt.

Black jacks part 1

I had planned to do this as a single post, but I’ve changed my mind as it would be too big. This first post will present the evidence and the second will show how I’ve made my jacks and will discuss some of the difficulties and some things I’ve found. From my point of view, jacks and bombards are the pinacle of leather vessels, there’s a purpose and elegance of form that isn’t so apparent in the other containers.

Oliver Baker, a gentleman collector writing in the late 19th century, appears to have interviewed craftsmen who, if they didn’t make leather jacks, saw them being made in their youth. He wrote a detailed account of the production, pulling it from publication as he was worried that he would enable the collectors’ market to be flooded with good copies rather than the poor work he railed about (many his signs of a counterfeit jack feature on the rubbish peddled at medieval faires and more worryingly, by English Heritage at their stores).

Many people therefore claim that there’s nothing about manufacture in Baker’s work, but if you look in the earlier chapters and the section he did print on making jacks, you can pick up almost the complete story. It all revolves around this picture on p188.

Baker Figure 72

Fig. 72. Wooden moulds and rings for making jacks at Messrs. Merrywether’s, Greenwich. (Each core has an associated pair of rings and one ring of the pair is smaller than the other.)

I’ll quote the sections of Baker that hint at the technique or manufacture or indicate decoration methods:

[p76] …there are incised lines on the spout portion arranged in a pattern not unusual in jacks of the 17th century.

[p108] JACKS WITH LIDS.
The jack in its usual sphere did not require a lid, and was seldom made with one. The lid is an addition and not part of the original vessel in the majority of those I have examined. The only instance I have found from old documents occurs in the inventory of Sir John Gage’s goods in 1556: “Item iij newe blacke jackes of lether wth cov’s, for the hawle. Item iij other old black jackes wth oute covers for the hawle.” (Sussex Archaeo. Coll., p. 125.)

[p122] This smaller one is of unusual shape, as, instead of the ordinary circular base, it is longer from front to back than from side to side, measuring 9 inches by 8. This is very unusual, as jacks are almost invariably circular in plan, the base being round and the top shaped for pouring from, according to the fashion of the period or the taste and fancy of the maker.

  [p132] There can be no doubt that the ornate handles of these smaller jacks must have been stitched when their shape was only roughly developed, and that they were cut into shape afterwards. The lines of stitching are outlined with incisions previously made in the leather as a guide; and after being stitched the ornamental contours were cut out with a sharp knife as tracery is cut with a fretsaw, as close to the threads as was consistent with safety.

If the complex handles he’s talking about are made the same way as the simple handles, this last statement is inconsistent with figure 70 on page 188. The figure shows the shape of the leather for a jack with the handle already cut. I take this a schematic diagram of how the jack would look, if it were laid out flat again after forming and stitching. I also reserve the right to be wrong on this point, but can’t see why there’d be different ways of cutting the handle depending on the complexity of the design when it results in a better finish even on the simple triangular handles. Cutting the handle before shaping would result in the handles being stretched excessively during the moulding stage.

Baker Figure 70

Fig. 70. Shape of the leather before being made in to a jack. (I think this is one of those omissions made to confound copyists. Note that he doesn’t say “before moulding”.)

[p179] There was, however, in 1891, at the Hospital of St. Cross, near Winchester … an actual eye-witness of the making of leathern jacks. One of the Brethren, who was once connected with the leather trade, remembered to have seen in his youth an order executed for four jacks for Winchester College. …

The Brother of St. Cross also remembered in Kings-gate Street, not more than two hundred yards from the College, the shoe-maker’s shop at a house which [p180] is still standing, where more than sixty years before he saw four leather jacks made. The particulars he gave me of the process have been of considerable interest in supplementing the knowledge obtained from a study of the vessels themselves, as to the manner in which they were made, and I had written for this chapter a long and detailed account of the method pursued. It seems, however, desirable not to print it, as the value of old jacks and bottles having increased, the temptation to make imitation ones has become greater within recent vears and I have decided to omit most of the details.

[p182] THE MAKING OF A BLACK JACK.
In making the leather pot or black jack only two pieces of leather were cut from the hide. The strips for thickening the seams would, of course, be taken from the scrap. The larger of the two was so cut as to include the handle and the body of the pot in the same piece (as shown at Fig. 70, which are given to scale from actual examples), the shape depending on the design of the jack. A new jack was pitched on the inside and blackened on the outside. This lining of pitch kept the leather from contact with the liquor, and prevented it penetrating and softening the leather. …

[p183] The jacks which the Brother of St. Cross remembered to have seen made early in the 19th century were blackened by being painted over with ink, and finished with a polish of black sealing-wax dissolved in spirits of wine. …

It is an interesting fact that at Messrs. Merryweather’s factory at Greenwich black jacks continued to be made down to the middle of the 19th century, and still more interesting that the great wooden blocks and rings on which they were modelled are still in existence. In one old corner of what is now a vast establishment for the making of fire-engines and kindred appliances, are a number of odd looking wooden objects much like big skittles upside down. (Fig. 72.) These cores or blocks appear to be of considerable age, and are certainly more than a century old. As can be seen by the sketch they are not like jacks in shape, because their necks are unduly prolonged and the portion which modelled the vessel’s spout is a separate piece of wood. This arrangement enabled the wooden core to be more easily withdrawn after the body of the jack had been worked in a damp condition into the required shape and dried on the block. The bottoms were moulded separately on iron rings (a number of which have been preserved with the blocks) and after drying were stitched into place.

[p184] MAKERS’ MARKS.
… Initials are very commonly found on bottles, and not seldom on jacks. When impressed in the leather with a stamp they may be regarded as those of the maker, as it could only be done successfully when the leather was wet and supported by the wooden block inside…

[p188] OF SPURIOUS JACKS AND BOTTLES.
… Perhaps the form most usually taken by these fraudulent vessels is that of a plain mug of leather. It sells as a black jack, but requires no great amount of time or expense to produce. The varied contour of a real one would require patience and skill to copy, whereas a mug with straight sides is soon turned out. In such false pots the bottom is often flush with the sides, an invariable sign of a sham. The genuine jack had always a deeply-recessed bottom, (the best way to make it water-tight), as the seams projected considerably and the bottom (always being liable to “swag” with the weight of the contents), might bulge so as to wear through or prevent the pot standing. Another point to remember is that all jacks with handles stitched on are shams. In genuine ones the handles are always a part of the same piece of leather as the body of the vessel and continuous with it. This is practically invariable…

My apologies for quoting huge slabs of text but I wanted to make sure each remark was in context. To save an equal amount of text, I’ll paraphrase Baker’s comments about the shape of the handles being a useful guide to dating. Generally, up to the middle of the seventeenth century, handles are triangular in shape and start with a small step down from the top of the jack. Later jacks have a more curved handle further down the side.

Any method of production must take all of these requirements into account. The base must be formed from a single piece of leather, worked over a round former in some fashion. The body must be made cut as a single piece of leather, and at some point in the process before stitching begins, the waste around the handle must be cut off and made into the reinforcing pieces. The body should be shaped around a wooden core with a removable piece for forming the spout. Stamping or carving should happen while still on the block and finally, the handle should not be finished until after the stitching is complete. Even with all this, Baker was comfortable he’d left enough information out to make it impossible to make good fakes. Given Baker’s omissions, I feel it is fair to add extra steps or equipment within the limits of the technology available at the time of the one you’re making.

The second part in a week or two (or three)  is about my attempt to fill in the missing detail. It is entirely conjecture, and draws heavily on the work done by Greg Stapleton of the Royal Ontario Museum. In the meantime, feel free to comment, point out logical errors or posit your own theories.

Destructive Testing Black Dye

In the store book of Charterhouse School, Godlaming is an entry under the year 1618: mending of pottes and pannes with waxing clensing and colouring of Jackes xiiiis. (Baker, p73)

While nicely justifying my use of beeswax, it refers to the practice of recolouring black jacks. Jacks, generally being black, were coloured with with a particular type of dye that contains a quantity of iron in solution. The iron reacts with the tannin in the leather, forming ferric tannate. There are any number of recipes around covering a wide range of preiods. Some start with oak gall in an iron pot , others with iron scale or even hot iron in an acidic solution (Theopolus, Bk1, Ch38). It tends to be a very dark blue-grey, which darkens to black on
application of wax, tallow or other forms of fat. For a comparison see What Tallow Does to Dyed Leather. So how often would it need to be redyed, or would it just need retouching on the scrapes and rewaxing be sufficient for the rest?

Some years ago, I was attaching a leather rim to a shield and left an offcut outside with a few iron tacks sitting on top. The following weekend, after a few showers of rain (yes, kids it used to rain in Australia once), I discovered the leather fairly crisp from having all the remaining fat washed out and a strong black colour. A few friends and I had been having a pseudo-argument about colourfastness of medieval dyes in the letters pages of the magazine New Hedeby. Never one to miss an opportunity to do some extreme testing, I cut the black leather in half, nailed one half to the fence and sent the other to one of these friends who, at the time, was living in Port Hedland. They keep the sun turned up to 11 all the time in Port Hedland. He also attached his to a post in full sun.

The results? Mine was still black when about 10 months later the fence blew over. His continued to be black until two years later, when the leather finally crumbled to dust.