Requirements for printing originalsTechical requirements
The digital original is:
1. only PDF / X-1a: 2001 (ISO 15930) compliant, ie on request
Ready-to-print composite PDF with CMYK or CMYK and spot colours
2. made using the Adobe Acrobat Distiller PDFX-1a setting and which has preferably passed a preflight check,
3. the margins are 3-5 mm on the outside, the clean format of the print is in the middle of the PDF page, without cut marks or at least 3 mm outside cut, the resolution and colour resolution of the images correspond to the printing process, other generally accepted rules for prepress have been followed.
For visuals of digital originals and sheet montage control is necessary according to the final result (including covers, inserts, etc.) folded and stapled or otherwise certified printout, in the case of leaflets, etc., the possibility must be ruled out mistakenly fold it. If adding a printout does is not possible and the publication contains unnumbered pages or additional elements have a mandatory layout plan describing the content, etc. to check their order.
Bleed 3-5 mm, 10 mm for large format work
All objects up to the print format must extend 3-5 mm beyond the edge so that no white surface is visible due to shifts in folding, binding, cutting, etc. It is important to take into account the cutting margin when preparing the design elements and framing the pictures, because otherwise something important may be cut off. It should be noted that texts and other critical design elements should not be closer than 3-5 mm to the edge, in the case of large format works 10-15 mm. Lines parallel to the edge of the page show the slightest post-processing error. It is advisable to leave the blade on each edge regardless of post-treatment.
Black and overprint
Overprints must not be defined for coloured objects (except 100% black). Black overprint must be added to black design elements and text (100% K) on coloured backgrounds.
For black surfaces where you want to avoid overprinting (for example, an image or background passing through a black box covering it), use black overprint - CMY: 1%, K: 100%.
When designing, it must be taken into account that all black objects (100% black texts and backgrounds) are made overprintable, meaning black overprint is added automatically in the printing house in order to increase the print quality.
Line graphics must not contain more than two sub-colours printed on top of each other.
Newer versions of photo editing, graphics, and layout programs offer the ability to leave a portion of an image transparent, add a drop shadow, or use a similar effect. When creating a PDF with the PDFX1-a standard, they do not cause a problem, but for newer versions of PDF, for example, the print result depends on the printer or RIP often used and is therefore unpredictable. Attempts by programs to realise transparency in printing in other ways result in a large and potentially problematic PDF.
Most print colour and image problems start with poor image processing and / or Photoshop colour separation parameters that are not set for the printing process: ISO 12647-2 profiles for different papers are not considered.
Before you get started, make sure to check your monitor settings (Start -> Control Panel -> Adobe Gamma or the calibration system you are using) and make sure that the appropriate ICC profile for the paper you are printing is selected in Photoshop.
For digital printing, it is recommended to use the Fogra39. icc or ISO_coated_v2_eci.icc profile.
Laser printing digital devices also allow Fogra39 for uncoated papers. achieve a colour space corresponding to the icc profile. However, if there is a desire to achieve a colour space corresponding to uncoated paper, PSO_Uncoated_ISO12647_eci icc profile must be used.
As even the best paper and printing results in a significantly lower colour range than nature, the goal of image processing is to make the most of it:
1. In each image you need to first set the lightest and darkest point, a good tool. In Photoshop, there are Levels on the histogram that show the brightness in the image;
2. Most images benefit from a slight increase in contrast, and it is often necessary to make the image a little lighter or darker, the right Curves tool.
3. Bright colors can be obtained from two sub-colors, the addition of the third reduces the colour saturation, for example, salad green consists of yellow (up to 100%) and cyan (approx. 60%) and the addition of magenta gives resulting in dark spruce-green; Selective Colour is best to remove excess colour; Hue / Saturation
4. Digital sharpening is necessary even for very good original images, because the raster tends to reduce the sharpness of the image, in Photoshop the tool is Unsharp Mask.
The resolution of the images in the design (dpi) for small prints must be at least 250 dpi - for large formats 150 dpi. Digitally increasing the resolution of low-resolution images to the required value is considered a deliberate action by the designer.
Automatic file checking does not detect this. In the publication, such images look like pixelation.
Colour space for all images and vector objects - CMYK. Pantone tones, RGB, Lab, etc. are automatically converted to CMYK, which can significantly distort the colour tones desired by the customer. Colour resolution refers to the conversion of an image in the RGB colour system used by a scanner, digital camera, or other input device to a colour system suitable for the printing device, which is CMYK for four-colour printing. Colour separation converts an image from RGB to CMYK, or colour separation during image processing in Adobe Photoshop or when printing from a layout program. The colour separation software takes into account the parameters known about the printing process (settings in Photoshop or ICC profile) and tries to achieve a result as close to the original as possible within the capabilities of the output device.
It is recommended to do most of the image processing in the RGB colour system and to create the CMYK resolution by generating the PDF using the ICC profile corresponding to the printing paper.
In order to print CMYK colors on coloured or transparent material, the whole design is needed, including the so-called white elements and texts, also make a White Under layer, meaning that all the elements that need a white background print are duplicated on the top layer and everything is in spot colour, called White Under, and overprint. To better see if White Under has everything it needs or a spot to be in a tone, n. M 50%
If there is only white printing, the spot name must be White Ower Varnish as the spot colour Varnish and set to overprint.
Since everything is printed at once, you don't have to make separate pages for spot paints and varnishes.
Die cutting drawings
1:1 drawing in vector graphics. Please avoid double lines and hiding lines.
The figure shows Grains = red (spot), Noodles = green (spot), Perfos = yellow (spot).
Special shape cutting or ESKO
All lines must be set to overprint. The thickness of the stamping line is 0.4 mm and there must be no double lines.
Originals not meeting the technical requirements
The printing house has the right to reject material that does not comply with the technical requirements submitted by the customer.
In order to ensure print quality, the printing house has the right to make unavoidable corrections to the customer's files.
The costs of reprocessing the material that does not comply with the technical requirements submitted by the customer, as well as the costs caused by the material that does not comply with the technical requirements shall be borne by the customer.