Photogravure

Photogravure printing is a method of printing high quality images using photographic and etching techniques.

History

The earliest forms were developed in the 1830s by the original pioneers of photography, Henry Fox Talbot in England and Nicéphore Niépce in France.

They were seeking a means to make prints that would not fade, by creating photographic images on plates that could then be etched, which could be prited from a traditional printing press.

Photogravure in its mature form was developed in 1878 by Czech painter Karel Klíc, who built on Talbot’s research. This process, the one still in use today, is called the Talbot-Klic process.

Over the course of time political, economic and aesthetic forces edged photogravure into retirement, witnessed its revival in these days.

How it is done

Photogravure and gravure prints have warm blacks and an amazing range of subtle gray shades.

Preparing the printing plate:  A pure copper plate, is thoroughly cleaned, its surface highly polished and its edges beveled. Next it is evenly dusted or sprayed with an acid resist of rosin or asphaltum, and heated to make the resist adhere.

Preparing the Image:  A positive transparency is made either from an original or copy negative. This film positive is then contact-printed under ultraviolet light to a gelatin-coated paper (known as carbon tissue, made light sensitive by soaking it in a solution of potassium bichromate) and dried.

Transfering the image to the plate:  The image-carrying tissue is adhered to the plate. This is soaked in hot water softening the gelatin and allowing the paper base of the tissue to separate. Portions of the gelatin that received little or no light during exposure to the transparency remain soluble and slowly wash away. This gelatin image called a resist, is then dried.

Etching the plate: The plate is placed in a succession of etching baths. The result is a plate with many minute reservoirs or cells of varying depths tamiflu dosage for adults. During printing, the deeper cells hold more ink, creating the darker areas of the image.

Printing the Gravure:  After the plate has been thoroughly washed, the gravure is printed – on an etching press. Stiff ink is spread over the entire plate and worked into the recessed areas that form the image. Next, the surface of the plate is carefully wiped, leaving ink in the pits. The plate is then positioned face-up on an etching press. The artist places a piece of dampened, high-quality paper over the plate then covers the paper with etching felts for padding and passes this through the press. The rollers force the paper into the small depressions that hold the ink, creating a printed image.

Today

Photogravure is a time-consuming, labor-intensive, costly process used today only by fine-art photographer-printmakers. The most prominent of artists today are James Craig Annan, Peter Henry Emerson and Alvin Langon Coburn.

Commercial printers, presently use two allied forms of photogravure for high-quality reproductions, Screen Gravure for regular grid pattern and Rotogravure for very large press runs (commonly seen in Sunday newspapers)

Video

Sources
http://www.finerareprints.com/articles/photogravure.html
http://www.photogravure.com/
http://en.wikipedia.org/wiki/Photogravure