Tornacum, copper printing plate

Printing plate from map of town Tournai in Belgium.

Engraved in to copper.

Size of the plate is 45x55 cm, width 1 mm.

Country and Period of Origin

Tornacum, map from 1649,

Drawn by: Blaeu J in Netherlands

Copper engraving
Size: 38.5 x 50.5cm (price of original coloured print is 700 €)

Webpicture of the map in size of 750x570 pixel 72 dpi

Copper in the printing plates become general in 15^th and 16^th century. I selected to use this special map to engrave, because: I visited the town in summer 2007, the map is beautiful, and town was one centre of the tapestry industry.

Copperplate:

The used copperplate is 1 mm thick and it had a plastic foil on other side of it. Used thicknesses in the plates has been 0,7-1 mm. The work is quite large, and I decided to use thicker plate, that it would not bend too easily.

In the period plates, coppersmith must take care that the hammering marks are not too visible. In the modern plates you can often have a foil on the other side, and that is how you do not need to polish it before engraving.

I filed edges and corners of the plate to get them round. It helps to keep your hands and print canvas undamaged.

Drawing the image:

I loaded picture of the map from the web. Unfortunately the map is so rare, that I have found it only from one place. The resolution of the file is not good enough to see smallest texts. Knowing the poor resolution I still wanted to use this map.

In the photoshop program I turned the picture in to mirror image (reverse), and printed it in the scale of the original map.

I attached the carbon paper behind the print and attached print in to the copper plate.

There was a plastic film on the other side of the plate and I took it away just before I attached the image in to that same side. I drew the map in to the plate.

Resolution of the file was so small, that there was no possibility to read texts of the description cartouches. That is why, other cartouche has left empty, and in to the other has been engraved my own name as engraver.

Tools:

While the picture was drawn I took the papers away and started to engrave it.

It was very difficult to find a suitable tool for engraving. In the Finnish language there is only one word for the tool, which has in English five versions, which has a small differences. My sources did not specify what kind of engraver was used, that is why it was difficult to find suitable tool for copper. As a result from it, is that I have now tools for wood, gold, silver and copper. The name of tool used with copper is burin.

After few tests I found out that the only useable burin type was square. Lozengo types needed to push too deep in to the metal, and that is why they slipped too easily. In the square type blade of the burin is sharpened diagonally at one end and in the lozenge it is in V-shape. Burins are available in many sizes. I used the smallest one.

The other tool needed is burnisher or scraper, which is used to cut the burr away.

Engraving:

The engraver used a burin pushed across the surface of the plate away from the artist. The palm was used to push the burin and it was guided by the thumb and forefinger. The action of engraving produced thin strips of waste metal and left thin furrows in the plate's surface, to take the ink. Any burr left on the edge of the engraved lines was removed with a scraper.

The highly skilled engraver uses the burin to cut an image, as a series of lines of varying width and depth, that are a translation of the tones and shadings of the artists original work. Deep lines hold more ink than shallow ones, producing a darker tone when printed.

The technique and the tools are same today. 

Engraving of the whole plate took about three months, approximately 120 hours.

 

When all the lines were engraved I polished the plate with polishing cushion. I tried to polish away all the sharp ends of the lines, burrs and scratches. It is very difficult to polish the whole plate so smooth that the colour does not stick in it.

Printing:

Next I printed a test dump:

Intaglio colour was mixed with dump oil and then poured until it was fluid. Then the colour was spread all over the plate with a paddle. Next the colour was wiped away from the plate with a non-spongy paper, that the colour would remain in lines.

 

Same time I had, 300gr non-acid, paper in the water moistened.

 

The plate was placed on the press table on the sheltering paper to keep press clean if there is colour on the back of the plate. Over the plate was placed the moistened paper, without moving it on plate. Plate and paper was covered with a cloth and whole table was moved through the press.

Printing plate was cleaned after the print with turpentine from the colour, and turpentine was removed with a Sinol alcohol.

I checked mistakes of engraving from the print and polished and corrected them.

The final prints were made in the same way than the test print.

It took 45 minutes to print one map.