Concepts that every designer should know for the graphic printing process

Normally, when we refer to creative processes, we tend to give free rein to our creativity to come up with concepts that, otherwise, would not cross our imagination. However, it is very important to take into account the subsequent processes and know the creation possibilities we have, since an amazing graphic that, for whatever reason, cannot be executed at the printing level is of little use.

Learn to manage design tools it is not easy. The countless variety of configuration options means that many of the ins and outs of the processes we carry out are forgotten, and we remember them on the day we need to print our part and, oh, surprise: we have configured everything wrong from the beginning . Has it happened to you? U.S. too.

Therefore, to focus the effort of the creative process on something useful and achievable, we must have certain notions about the basic stages and concepts of the pre-press process. Below we give you all the information you need to configure your files for printing correctly.

preimpresión en el proceso gráfico

The importance of pre-press in the graphic process

This may be the first time in your life that you have heard of the term pre-press, and you are not alone, although you should know that every time you have printed a document, you have carried out an associated pre-press process. Whether the development was adequate or not is another story.

The mission of prepress processes is to avoid imbalances that may occur during printing work, whether in the production of a graphic, a book, a catalog or an agenda. That is, we are talking about an intermediate phase between design of a document and the final impression of the product.

Adjust, save or export Illustrator and Photoshop files for printing: essential concepts in the pre-press process

There are certain terms that we must have under control to understand the processes we must carry out before printing. Knowing these concepts and mastering them will help us understand the importance of correct file configuration and how the different parameters affect the results of your printing.

What resolution to use in the files.

The resolution of a file refers to the amount of detail that a file has. digital image. The higher the resolution, the greater the level of detail that we can see in the image. Precisely for this reason It is very important that the resolution of our files is appropriate for the printing mode and size. It would be a shame to invest days of work on a project and, when it comes time to print it, to realize that certain processes have to be repeated because we have not correctly adjusted the resolution of our file.

To better understand the concept of resolution, we must first clarify two concepts that usually generate a lot of confusion: what are PPP and what are IPR. Both terms are used to refer to the resolution of an image, although each indicates different indicators:

PPI or PPP – Pixel per Inch or Pixels per Inch

The pixels per inch They refer to the resolution of the monitor. On a standard screen, the resolution displayed is 72dpi. Therefore, if we are going to use our image only for digital use, this resolution will be more than enough. It is important to note that in a digital image, size is measured in pixels (height and width).

DPI – Dots per Inch

In Spanish, DPI means “dots per inch”. This term is used to print and scan images and refers to the resolution and quality of a print: the higher the DPI value, the greater the level of detail in our piece. However, we should not exaggerate. Adding a crazy dpi value to your piece would generate images that are excessively large and would be very difficult to work with.. Furthermore, from a certain DPI value, the result barely changes, since our eye does not have the capacity to perceive such minute changes. A common printer works with values of 300 dpi, which is more than enough to generate good results. The size of a printed image is measured in cm.

In short, they are two terms that talk about resolution for two different media: screens and printing. Although resolution is a term we work with every day, it can cause confusion and slow down the process. Therefore, although it may seem like the most basic thing, the most effective recommendation we can give you is to strictly follow the file configuration criteria indicated by your printing center.

Surely, at this point, you have more questions than answers. If they are two different concepts, How can I get it right when setting my image for printing? To obtain the best results, we will take into account two factors: the resolution we need for printing and the physical size in which we want to print our piece. Let's see it with an example to understand it better:

Let's imagine that we want to print a piece in a size of 40cm x 15cm.

  1. The first thing we need to do is convert this value to inches:

15.74'' x 5.90''.

  1. Then, we will multiply this value by the resolution we need to print. Depending on what you want to print, this information will vary. Printing a book, which will be seen up close, for which we will need values around 300 dpi, is not the same as printing large formats such as a billboard that will be seen from afar, since in this case we can reduce the resolution to even more. 150 dpi without affecting the perception of image quality. Since in our case the piece will be small and we will see it up close, we are going to multiply the size in inches of our image by 300:

4722px x 1770px.

This will be the size we need for our digital image if we want the printed piece to have an adequate level of detail in the 40x15cm size.

Differences between RGB and CMYK

Another factor to take into account is the color modes in which we have configured our document. We must pay attention to this aspect, since an incorrect color configuration can bring us unpleasant surprises when receiving our printed piece. First of all, let's look at the differences between the two most used color modes for design:

RGB

This color mode gets its name from the acronym “Red, Green, Blue.” This mode is intended for designing content for monitors (computer, television, mobile...) and works with the color information that we can transmit through the light of the screen.

In this case, there is a additive synthesis to get the colors we need. What does this mean? That through the sum of the primary colors (red, green and blue) we can represent any color. We start from the color black (absence of light) when we are at the minimum values of each light, and we obtain brighter colors as we increase the values, until we reach white at the maximum. At the intermediate points we can obtain any color through the millions of combinations of the R, G and B values.

Qué-es-rgb

CMYK

This color mode, also known as four-color, gets its name from the acronym “Cyan, Magenta, Yellow and Key Black.” This mode is used for printing designs and works on the color information that we can transmit through the inks.

This time, there is an opposite case to the previous one and we work with a subtractive synthesis. That is, the colors individually are brighter than the mixture between them. If we mix the three colors, we will obtain a very dark tone. The sum of colors in the ink option never results in pure black, although it is quite close. Therefore, we will need to add a fourth value to our print: Key Black (pure black) for cases in which we need a total absence of color.

Qué-es-cmyk

Therefore, for our document to be configured in the correct color mode and the tones to be faithful in printing, we must make sure our document is in CMYK.

PANTONE

The Pantone company makes available to users a registry of more than 1,100 colors defined by a unique number followed by a letter. In this way, they have generated a standardized color code which is widely used in the design industry. Although they are also created with ink, these colors are difficult to imitate through CMYK mode, since the Pantone system uses 15 pigments as a base, including black and white.

Printing in Pantone is usually more expensive, since each job is printed individually. Therefore, a four-color print will be more expensive than a two-color print.

What are cut marks and bleeding and what are they for?

cut marks

Crop marks are essential for guillotining in printing. These marks indicate the size of the piece and where we want to cut it, so it is very important that we pay special attention when we are configuring this aspect.

Bleeding

The bleed is an indicator for printing that establishes the point to which the piece must go so that there are no white margins. This is implemented to compensate for possible micro imbalances that may exist in the use of the guillotine, since the cut is not always perfect. This is especially important for two-sided work. Therefore, the blood should not be a blank margin, but should also contain the piece. 3mm per side is an ideal value for the bleed of our document.

How to prepare a PDF with bleed

Let's see how to export files in PDF for printing from Illustrator and InDesign, two of the most used software for design and layout of parts.

Step 1

We leave a 3mm bleed in our document.

Como-marcar-sangrado-para-imprimir

Step 2

In the menu, we select File > Save as… And we select the “Adobe PDF (pdf)” format.

Como-guardar-un-archivo-en-pdf

Step 3

In the save menu, go to Marks and Bleeds and activate the “All printer marks” box. Afterwards, we give a value of 3mm to the bleeding on all sides.

Como-hacer-marcas-de-recorte-para-imprenta

Result

We will obtain a document similar to the one you see below, with the marks prepared so that our design is just as we imagine it.

aprende-a-preparar-documentos-para-imprenta

What are the different techniques or types of printing

Finally, let's look at the options we have to print our designs. Each medium and each design may require a different type of printing depending on the results we want to achieve. There are many printing techniques, but below we will show you the most used ones:

Offset

This printing method is carried out with aluminum, stainless steel and plastic plates. Some of these plates are coated with a photosensitive material that, after a reaction to very intense light, is printed on the surface of the printing canvas. This technique is widely used in brochures, packaging, catalogues, magazines...

Serigraphy

It is one of the most widespread methods in printing parts. This technique is effective on various materials, such as paper, metal, three-dimensional surfaces... in addition, it achieves high quality results.

Ink-jet

This method is the one used in traditional home printers. Images are reproduced thanks to ink nozzles. Currently, there are printers that reproduce high-quality images in a short time.

Stamping

It is a hot stamping technique that uses thermal transfer through a foil with a metallic effect. Traditionally, this process was carried out using dies, but currently there are digital machines to carry out smaller runs.

Main mistakes you should avoid in pre-press

Once the entire process is finished, it doesn't hurt to take a general look at the most frequent errors in printing, to make sure that we are not making any of them. Here we leave you a list of the elements that we review without fail before sending our design to the printer.

  1. Bleeding and cut marks: It is basic and one of the most common mistakes. Take a second look at your design to check that the bleeds and marks are placed exactly where they should be. Don't forget that a guillotine is going to pass through there and there will be no turning back.
  2. Orthography: read, reread and read again. It is essential that the content of our design is perfect at a spelling level. Correct writing will provide rigor and credibility to both the message and the design that contains it.
  3. Page orientation: It may seem absurd, but many of the errors in printing are directly related to this setting.
  4. Proportions and sizes: It is important to take into account the proportions of the designs depending on the products we are going to print. In some cases, for standard processes, there are templates that can greatly facilitate these processes and help us work on correct proportions.
  5. Plan it ahead of time: This may be the best advice we can give you regarding the pre-press process. Not only do we base ourselves on the principle that rushing does not lead to success, but on some occasions, we may encounter printing processes that take a certain amount of time to complete. Certain finishes, bindings or other design options require time to be generated and finished, so not having enough time for printing may force us to opt for the least suitable option for our project, for the simple fact that it is the which requires less time. Furthermore, with correct time planning, we will have room to correct those errors that, despite having given all our attention, may have escaped.

In principle, by following these tips and paying attention to each phase, we should have no problems printing any of our designs. However, if what you want is to be able to face any design challenge that comes your way, take a look at our programs Bachelor in Graphic Design with Solent University, they are made for you!

 

Did you find the article interesting?

Leave a Comment