The editor is also responsible
for delivering originals to pre-press, the third stage in the development process, where large numbers of specialized workers handle
the most modern technology in the field of electronic pagination.
When the pagination of a book is finished the digital files are sent to Porto Editora's special industrial unit - Bloco Gráfico.
Bloco Gráfico, Lda, is located in Zona Industrial da Maia, X section, and it is part
of the Printing section - Artes Gráficas, which is mostly dedicated to printing and binding
of books related to education (school textbooks, dictionaries, etc.).
Output to a printing plate
The first stage of work at the factory consists in outputting the content of the digital files directly to a printing plate
(CTP - Computer to Plate). This process is monitored by two modern machines controlled by computer.
The plate coating undergoes a chemical change during laser exposure, in a process called development,
allowing the text and the images to be transferred to the plate.
At this stage of the production process, the plates contain the pages that will be printed, to create a book.
The content of book can be exclusively text (usually, printed in one colour), or it can also have photographs, drawings,
diagrams, etc. A, so called, four-colour process is used to print a book with several colours. This process,
whereby illustrative material is reproduced in four different colours: cyan, magenta, yellow, black, creates four different plates.
These colours combined produce a complete range of colours.
After the development of printing plates, these are sent to printing machines. Besides feeding printing plates, these machines feed the ink and the paper. This way, the pages from the printing plate are printed onto paper - from one single plate thousands of pages can be printed.
Rotation of the rollers
in these machines takes the printing plate into contact with the ink, which is then deposited on another roller, this one made of rubber. It is this roller that then makes contact with the paper, adding colour to thousands of blank pages. Each sheet of paper is usually printed with 32 pages of a book, 16 on each side.
Binding gives the final form to the book
First, the sheets of paper are folded in such a way as to form small booklets of 16 or 32 pages each.
The next stage is the combination of the different booklets that will form the finished book (arrangement),
after which the seams are sewn, keeping the pages together. The following stage is the binding of the cover to the book;
in the case of paperback books, the binding is done on spine of the book, followed by the final trimming of the other
three sides; in the case of a hardback book, the pages are first trimmed to size, after which the first and last pages
(designated guards) are glued to a previously produced hardback cover.
Bloco Gráfico industrial unit, custom built, has modern and functional fittings and its activity is developed in
a safe and healthy way thus controlling the emission of liquid effluents, solid residues, air emissions, level of noise
as well as energy, water, raw materials and other materials consumptions.
Bloco Gráfico, Lda Policy
The Environmental Management System, implemented according to ISO 14001:2004,
was certified by APCER on January 2006 and it allowed the control of these issues as well as the compliance of the environmental legislation, the prevention of pollution and the improvement of the global environmental performance.
The last stage is Distribution, that is, the book is distributed by bookshops all over the country, and in some cases, in other countries. Do not forget, also, that you can always turn to the bookshops of Porto Editora, where experienced and attentive professionals are at your service.