Data preparation standards
REQUIREMENTS ON CtP DATA PREPARATION
How to prepare files for imposition
We suggest using the following nomenclature of files, for example: book_title_001_032.ps – file containing pages from 1 to 32. Please send each page separately. Do not join other pages, for example grouped in two or more pages. If case the book is of high volume, the file may be divided into several parts. Never use Polish fonts in file names.
Files ought to have an unambiguously defined page format and margins. A text column should be properly set onto the page (upper and spine margins). Select the “page center align” option while generating a file. In case a job is to be printed just to the edge of the page, 4-5 mm extra margin for proper cutting ought to be provided. Cutoff and matching marking gauges should be distanced never less than at least 4-5 mm away from net perimeter. Marking gauges are placed automatically by the imposition program, so there is no need to insert them within the files except for spine marking gauges and cover flaps creasing marking gauges. We advise to make sure a job has properly defined TrimBoxes and BleedBoxes.
Files should be saved either with pdf (*.pdf) formats or PostScript (*.ps, *.prn), which are subject to conversion into pdf files prior to the imposition phase. We accept both separated and/or composite-type files although the latter are preferred due to easier processing. Whichever mode is selected, very important requirement being to make sure there is only one format used for a given file.
In the case a cover is to be printed on both sides (pages: front and back plus 2nd and 3rd), please merge together internal pages of the cover but you need to provide for unprinted belt of the width equal to the sum of a book spine width and two 4 mm wide unprinted belts to be left for side glueing, each adjacent to a spine belt at its both sides. Within the cover file the cutoff marking gauges, spine marking gauges and – in case a cover has folded flaps (wings) – also flaps scoring gauges should be added. All these marking gauges should extend at least 5 mm beyond the net perimeter. Please bear in mind essential graphic elements (logo, texts) that are to be placed either on the first page or on the last page of the book block should be distanced from the spine edges by at least 9 mm. If neglected, these elements will hide within side gluing areas, which extend as much as 8 mm from the spine creasing lines. Same characteristic needs to be taken into account in the case graphic elements are designed to pass across from internal cover(s) onto the first/last page of the book block. Otherwise, proper geometrical matching may not be achieved. The drawing below illustrates those dependencies.
Files comprising data with regard to the enrichment of the cover (selective lacquering, gold plating, stamping) ought to be provided as separate pdf format in 100% Black color. Stamped or plated objects should be defined as vectorial ones.
The following information should be mentioned in the attached text file:
- numbers of vacant pages (if not provided within the above described files),
- net page format (size), upper and spine margins,
- number of pages,
- other relevant notes regarding assembly of the book.
Each component on a page ought to be defined in CMYK colors or special Pantone colors, as they were designed for printing. Each special color, not the CMYK ones, which is to be printed as an additional one should be precisely defined as per Pantone guide, with numerical code of the color and location of colored objects shown. In the case such information is missing, all additional colors would get fallen into CMYK separation files.
All fonts applied within the project must be attached to a PostScript or PDF file, used for exposure, or converted into curves.
We kindly request files to be delivered on a disc (CD-R, CD-RW, DVD-/+R or DVD-/+RW) or sent via ftp server – address as follows: ftp://ftp.opolgraf.com.pl, user: drukarnia, password: drukarnia (this account has an open access) or through e-mail: firstname.lastname@example.org (files up to 50 MB). Should you wish to open a private account (advisable), please send an e-mail with the name and addresses of the company; login and password will be sent in response.
- Imposition printouts (ozalids)
Upon completion of the imposition phase, a blueprint (ozalid) of each sheet will be printed (in slightly belittled scale – down to 92%). A complete set of ozalids will be shipped to a customer for approval. Should a customer find any error, he or she is expected to make a file correction and send it back to Opolgraf. An approved set of imposition printouts for a given job, bearing customer approval signature and date, with each error being precisely marked, should be shipped immediately to Opolgraf. Please be advised that without having them available a press operator will not be allowed to begin the printing operation.
NOTE: Ozalids serve only the content-related verification. Color printed are exclusively as indicatory overview, and do not reflect real colors.
- Digital proofs (for color-matching)
Those are printed for every book cover, flyer, banner aso. as well as for selected pages of a colorful book block. Upon a customer decision, selected pages’ color proofs can also be printed. A customer should indicate numbers of such pages as vital for his project in order for the digital proof to be printed.
- Other proofs for color-matching
Other proofs can also be used for color-matching. Cromalin, matchprint, aso. as well as a book printed in the past whether in Opolgraf or elsewhere. We recommend such an approach in the cases of books being published in series, when tone colors have to match not only the universal guides but also other items in series. Any detailed information will by highly appreciated as it will largely help a press operator to concentrate his attention onto the most important characteristic.