Aluminium to Zinc

The following are terms  are a starting point for those interested in trying these methods for themselves. It is an idiosyncratic list and does not claim to be comprehensive. Rather than repeat longer published work, references are given. The most useful and regularly updated of these is the research resource and practical guide at www.nontoxicprint.com/  (you do not need to sign in if you are not a member).  All the A&C Black printmaking handbooks are a useful resource.

ALUMINIUM

This is a cheap and versatile choice of plate material for etching, dry point, collagraphs or lithographs. It etches in a characteristic way due to the grain: it does not give an open bite like copper or zinc, but produces a surface roughness as it etches, giving a good range of tones with selective stopping out over a short period (about 6 – 8 minutes). After this point the surface begins to wear away and the darkest tones become less dark, doing test strips to gauge timing is useful. It may be carved with hand and machine tools and etching to differing depths is possible, but both copper and zinc are better for this being easier to carve and giving open bite.

COLLAGRAPH

A print made from a plate the surface of which has either been built up by addition of other materials or lowered by subtracting surface layers as with card.  The plates may be of metal, wood or card, but all will hold ink on their surfaces to a greater or lesser degree.Carborundum, sandpaper, dilute PVA glue, textiles, acrylic paint, torn paper, grout etc. will build up the surface which can be modified by blowtorching, adding drypoint or engraving depending on the base plate.

Robert Adam and Carole Robertson, Intaglio 2007 ISBN 0-500-515343-0
Brenda Hartill and Richard Clarke, Collagraphs 2005 ISBN 0-7136-6396-0
Ross,Romano, Ross, The Complete Printmaker 1989 ISBN 0029273714

COLOUR INKING

a) A la poupée – an intaglio method of printing several colours from the plate at the same time. Advantage, no registration problems; possible disadvantage is that the junctions between colours tend to be less sharp. Small scrim dollies, cotton buds or brushes can all be used to apply ink. Each colour needs wiping before next colour is applied. Smudging may enhance image.

b) Viscosity printing – intaglio and relief method of inking the plate. This prints several colours from the plate at the same time. It depends on the ability of an oily ink to repel a drier more viscous one placed on top and the converse, the ability of a drier ink to absorb and mix with a wetter ink placed on top. In addition to using inks of differing viscosity, rollers of differing hardness can be used to penetrate (or not) the different layers in a deeply bitten plate.

N Krishna Reddy  Intaglio Simultaneous Color Printmaking 1988 ISBN 0-88706-740-9  Without doubt the best and only detailed explanation of this
Ross, Romano and Ross as above. Excellent all round book.
Nigel Oxley  Colour Etching 2007 ISBN-10: 0713668202

DIGITAL APPLICATIONS

Modern printmaking books give details on how digital methods are used in their particular speciality, for example in making masks, transfers and image manipulation. Digital Art Studio by contrast offers a different approach combining inkjet printing with printing on a wide range of unusual substrates and layering of digital prints with more conventional printmaking or painting.

Karin Schminke, Dorothy Simpson Krause and Bonny Pierce Lhotka Digital Art Studio 2004 ISBN 0823013421 There is a later book by Bonny Lhotka, but this earlier one is more inventive.

DRY POINT

This is an intaglio process in which the line is incised into the plate by a sharp point, this can be anything that will scratch the surface sufficiently to hold ink. The line is softer than an etched one as the point leaves a burr which holds ink. The characteristics of the line vary with the angle of the ‘needle’ and the pressure exerted. Traditionally the plates were of copper, but now other metals, varnished grey board, perspex and drypoint plastic are common. The plates are relatively short lived as the burr wears down. Inking and printing are similar to etching. It is worth experimenting with plastic plates and printing them face down on dry paper with an increased pressure – Caligo works well.

ETCHING

Conventionally the image is drawn with an etching point through a ground protecting the surface of the plate. The plate is then etched by placing it in a bath of etching solution (mordant) for varying times. On completion the ground is removed, the plate inked and wiped and run through the press with a sheet of dampened paper. The resulting print is made from the ink held below the surface of the plate and is a mirror image of the original.

Nigel Oxley as above, and many others, Old ones of interest by WS Hayter or Ruth Leaf

FERRIC CHLORIDE MORDANT

The mordant used for copper and brass replacing nitric acid.

Robert Adam and Carole Robertson, as above
www.nontoxicprint.com/ 

GROUND REMOVAL

Acrylic grounds, Andrew Baldwin’s ground  and shellac will come off easily if the plate is submerged in a hot washing soda solution (about 1 tab per litre in a photographic tray or similar). There are now non-toxic paint strippers available, a Google search will list them.

LIFT GROUND ETCHING

Here the image is painted/drawn onto the degreased plate with a substance that can be dissolved/removed once a waterproof ground has been applied over it, leaving the image area only to be etched. Traditionally a sugar solution was used, but a thick mix of instant coffee works well and dissolves when covered with hot water. Latex or cooking fats like Cookeen can also be used, these wipe off after the ground has been applied. Each leaves a different sort of mark to be etched.

MONOTYPE

A single unique print made by drawing on a plate/plates and transferring this to paper. Masks (to stop ink transfer) and/or stencils (transfer of ink via stencilled shapes) may also be used. This is often combined with other types of printing such as intaglio, relief and litho, adding autographic marks that will differ between each print.

PHOTOCOPY TRANSFER / LASER TRANSFER

Photocopies and laser prints can be transferred to a degreased plate and etched. Place photocopy/laser print face down on plate placed on a wooden board. Cover with clean newsprint or cloth and iron with a domestic iron at the hottest setting to effect the transfer, this also fixes the toner. There are two hidden difficulties with this, firstly, toners differ in composition and some work well others not at all. Secondly the resulting etch differs between aluminium on one hand and copper/zinc. Due to the ability of copper and zinc to give open bite in non covered areas, which usually print ‘white’, the toner covered part acts like an aquatint (due to the dots per inch) and prints darkly. The opposite happens with aluminium, the toner area does not etch, so stays ‘white’ and the non toner area gives the characteristic darker etch. Interestingly if posterization is used in preparing the image the varying greys between the extremes gives a graduated etch with aluminium and there is no need for halftoning.

REDUCTION LINO CUT OR WOOD CUT

One plate, usually lino or wood, is used. This is cut progressively allowing a number of colours to be printed separately in sequence.

RESISTS

Acrylic-resist etching for metal plates is a non-toxic method of protecting the surface of the plate from the mordant. In both hard and soft ground etching the resist is usually some form of acrylic polymer.

a) Hard grounds may be pour-on (e.g. Klear floor polish,now discontinued, 2 coats), paint-on (e.g. Lascaux hard ground) or roll-on (e.g. Andrew Baldwin’s ground, www.printmakingstudio.co.uk ). Liquid hard grounds can be used locally as stopout out when etching progressively. The image is made by drawing through the ground with an etching point.

b) Soft grounds can be worked unset or set. They are used for the variety of marks that can be made while still damp, such as impressions in the ground by objects, direct or indirect pencil crayon marks, brush strokes, water sprays etc.

c) Degradable resists which break down in the mordant with time e.g. very dilute Hunt Speedball screen filler, animal fats, lipstick. Some give very interesting textures.

d) Backing resist. Radiator paint is mordant resistant, does not need removing after etching and is white so that notes can be made on back of plate.

Keith Howard, ‘The Contemporary Printmaker’ (2003) ISBN 0-9741946-0-3
Robert Adam and Carole Robertson, as above

www.nontoxicprint.com/    This is constantly updated as methods and substances vary.

SALINE SULPHATE SOLUTION

This has been developed as a mordant for aluminium, mild steel and zinc.
Keith Howard, as above
www.nontoxicprint.com/

It is a mixture of copper sulphate, salt and water in varying proportions. Many are given in the literature and the strength seems to affect the type of etch that results.

4 useful ones are:
a) 70g Copper sulphate : 70g salt: 1 litre water – gives good range of tones and fine lines
b) 100g Copper sulphate : 100g salt: 1 litre water – gives good range of tones faster
c) 140g Copper sulphate : 140g salt: 1 litre water – tones and good for degradable grounds
d) 200g Copper sulphate : 200g salt: 1 litre water – fast, good for getting deep etched areas

With zinc it is not necessary to use salt, the etch time difference is negligible and the etch finer without. The exceptions are
a) for very deep etches where with salt is faster
b) for Spit bite There is a recipe that gives 800g Copper sulphate: 1 litre water. Sounds nonsense, but it works, and quickly. Not much is needed and a small lidded pot will suffice, the mordant can be easily brushed on.

SCREEN PRINTING

In this process the image is transferred to the substrate by forcing ink through the open areas in a mesh stretched on a wooden or aluminium frame.. The non printing areas of the mesh are blocked by a stencil and do not print. Stencils vary from simple paper cutouts and directly painted marks to highly complex photographic images. Fine art screen printing uses many types to produce a single completed image, building up layers of translucent or opaque layers. Many different substrates may be used for example, paper, textiles and ceramics.

The following give accounts of the process from different perspectives

Robert Adam and Carole Robertson, ‘Screenprinting – the complete water-based system” (2003, reprinted 2014) ISBN 978-0-500-28425-4. Another excellent all round book.                                     Joanna Kinnersly-Taylor, ‘Dyeing and screen-printing on Textiles’ (2011) 2nd edition, ISBN 978;-4081-2475-8  This book bridges the fine art – commercial use divide.                                     Clare Benn and Leslie Morgan, ‘Screen Printing – layering textiles with colour, texture and imagery’, ISBN978-0-9551649-5-8 There are alternative approaches here that are interesting.

 ZINC

Advantages: softer to cut than aluminium, making shaped plates a possibility; uses  saline sulphate mordant as above; etch gives open bite making viscosity etching cleaner and clear that aluminium; is less expensive than copper.

 

OTHER REFERENCES

http://www.greenart.info/green/
www.ndiprintmaking.ca/
http://homepage.usask.ca/~nis715