Design Tips - Everything You Should Know About Offset

Posted by erika castilla lozano on


Very commonly, when we are studying graphic design, we leave in the background the most technical and boring part that turns out to be the previous step to printing, it is the well-known and tedious for many Prepress subjects.n.

In our days as students we are in full effervescence of ideas, in a period of self-knowledge, and we are more interested in finding out how far our creativity can go than in things as earthly as the basic rules to prepare a file that goes to press. In my school, the Production Techniques subject was the equivalent of gymnastics or crafts at school, we did not take it very seriously, of course deep down we thought that we would have time to learn all that when we were finally commissioned with real jobs, in the real life!! then we would see, now it was time to dream and create !!!r!!!

My case was very similar to the rest of my colleagues, but since I am the daughter of a printer, my father is a typographer and owner of a printing press, out of respect for him and his profession and it all has to be said, try to pay all the attention I could and certainly to shortly after finishing the degree, I discovered how wrong all future designers were in not giving almost importance to this matter, and how expensive we could pay when starting our professional experienceional…

Printers, as businesses, have two very clear objectives: to do the perfect job so that the customer is satisfied and also to do it in the shortest possible time, thus increasing productivity. In order to meet these objectives, it is essential that the designer prepare a final art that meets the basic standards, and although I imagine that many of the professionals who read this already know them.

I will explain them as a summary:

Color mode.

All files to be printed must be in cyan, magenta, yellow and black CMYK mode.). Full color images, whether they be photographs, illustrations, etc. can be captured on paper with only 4 inks. On the computer, when we are making our final art, we must make sure that all the images are in that color mode, because if they are in RGB light colors, suitable for viewing on the screen, websites, etc., and you take them to print, the The result of this conversion to 4 inks is unpredictable, sometimes the result is suitable, but other times it is a disaster, that is why in printing matters, it is better to leave the fewest possible factors to chance.res. In general, the colors tend to fade a bit when we go from RGB to CMYK, especially the blue ones.


Ideally, all designers, before starting our professional careers, do practices in the manipulation workshop of a printing company. It is there where one finds the meaning of all those requirements that demand so much from us when ordering a print. When our file has a background color, or an image that reaches blood up to the cut line of the paper, it is essential to extend that background or image about 3 millimeters outside the cut line. You must always comply with this rule, no matter if it is a business card, a flyer or a 120-page magazine.s.

Bleeds prevent unwanted unprinted white lines from appearing at the edges in your finished work. The guillotines usually have some millimeter of imprecision even in the work of plate, cards, flyers, etc., and the process of manipulating a magazine or book has many steps such as cutting, folding, stuffing, binding, etc., all that makes the bleeding is even more important and necessary for a satisfactory

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When our client wants to put much more text than what would actually fit on a page, or simply because our aesthetic sense betrays us, anything can happen !!, we can make the mistake of trying to reduce margins to the maximum. I'm not going to go into aesthetic criteria, but on a technical level it is very likely that you will run into a problem. Taking into account that the bleeds are necessary in case the guillotine cuts a millimeter or a little more on the outside of the cutting crosses, we must also leave enough space between the texts and the cutting line, in case that inaccuracy occurs but at the same time. Conversely, the guillotine cuts a millimeter or a little more inside the cut.e.

A margin around the perimeter of the document of at least 7 millimeters approx is recommended. By complying with this rule you will not risk the contents, which although they probably would not be cut, possibly they would be too close to the edge of the sheet giving an unprofessional appearance.

Magazine Margins.

For magazines, these margins must be higher and they are extremely important. As I explained with the bleeds, in the manipulation of a magazine there are many processes cutting, folding, stuffing, etc. And the more pages the magazine has or the thicker the paper, the more generous the margins must be. This is due to the fact that magazines, especially those with a stapled finish, are made up of booklets that go one inside the other, the central booklets suffer a displacement of a few millimeters towards the outside, the more pages the magazine has, the greater that displacement will be.iento.

You can do the test if you have a stapled magazine of more than 90 pages at hand, if you measure the first or last pages, you will notice that they are a little wider than the pages near the central ones, yes even if you have designed them all equal !! unfortunately the laws of physics do not forgive All this must be taken into account when giving margins to your files.s.

Resolution / optimization.

The images that make up our designs must be at 300-360 dpi. and in the final size at which they will be printed. Although it seems obvious, it is useless to buy an image at 300 dpi that measures 10x15cm, if later we are going to stretch it to a larger size the number of pixels does not multiply when we enlarge an image, but these are enlarged in size with what very our eyes will probably perceive them, it is when we say that an image is pixelated.da”.

It is also not advisable to use a very large image and then reduce it in Illustrator, InDesign or Corel Draw, the size and resolution adjustments are advisable to do in image editing programs such as Photoshop, in this way apart from avoiding possible defects in the quality of the images, we avoid overloading the file, that is, we optimize it to make it easier to work with it.

PDF format, the ideal.

Today, printers see the heavens open when the customer hands them a PDF file. In fact, more and more printers are supporting only these files. A well configured PDF file guarantees that everything we have decided on our final art will be respected by the printer..

The same is not the case with JPEG or TIFF bitmaps as these formats lack a lot of important information for printing. A JPEG or TIFF can be printed in good quality, but not without first having to explain in detail some issues such as what is the cut size of the file or how many millimeters there is bleed. A well-configured PDF has all the information a print shop needs.a.


When we prepare a file in PDF format it is advisable to embed the fonts. If your printing company supports other files, such as InDesign or Illustrator, Adobe programs let you create folders for printing with the option to package in which it will automatically include the fonts that you have used in your document.o.

If what you want to deliver is a Corel Draw file, my recommendation is that you convert all the texts to curves or make sure to attach the font when you deliver the file to print. Not taking these precautions can lead to some other unpleasant surprises, even when you have used very common fonts such as Helvetica or Arial, the version of your font may have differences with the version of the font that the printing press has installed on their computers.

Unintentionally activated overprint.

Many designers have had some unpleasant experience with the unintentional activation of a color overprint. In Adobe programs such as In Design or Illustrator, it is more common that the designer has activated overprinting in some of the colors in his palette without realizing it, the result once the work is printed can be disastrous. In both programs you can activate the overlay view in the view menu, it is convenient to have it active all the time to be able to notice this error. In programs like Corel Draw it is very difficult for this option to be activated by default.cto.
On the other hand, it should be borne in mind that most printers tend to automatically activate the overprinting of black to improve the final results, it is activated when the percentage of black is greater than 97 or 99, it depends on the printing press, overprinting black is avoided above all imperfections in texts on colored backgrounds, since it is almost impossible to perfectly adjust openwork texts.ados.

To play with the subject of overprints, it is advisable to have enough prior knowledge about it, there is a lot of very useful information online and you can always consult with your trusted printer, they will surely be happy to answer your questions.

And in general, these are the basic requirements to guarantee that your work turns out as you wish. Less and less printers are lending themselves to modify files created by others, and if one thinks about it carefully, they have compelling reasons not to do so, opening a file that another has created carries some risks and in case an error arises from that modification change of font, hidden layers, misprints the responsibility would fall on the printing press.ta.

So if you appreciate your collaborator, do not put him in the commitment to ask him to finish doing your work, he if he agrees to help you multiplies the risks, and believe me, he already runs enough in each process, from the start of printing until it is delivered the job.