Special print finishes in the graphic arts industry

There are various types of printing systems in the graphic arts sector. Each is characterised by three processes: pre-press, press and post-press. To deliver a high-quality product, it is not only necessary to ensure the printing is done to a high standard, but also to take into account the preparation and finishing of the print.

Table of contents:

• 1. Printing processes in the graphic arts
  • 1.1. Pre-press
  • 1.2. Print
  • 1.3. Post-printing
• 2. Large-format print finishes
  • 2.1. The most common finishes in large-format printing

1. Printing processes in the graphic arts

To gain a better understanding of the types of special finishes available in the industry, it is necessary to examine the differences between each printing process. The description of each stage provided below is general in nature, so as not to go into too much detail about each type of printing system. However, we will place particular emphasis on digital printing and examine the final process in greater depth: post-printing, more commonly referred to as finishing.

1.1. Pre-press

This is the pre-press stage, the process during which the job is optimised. Tasks such as scanning, colour proofing, film output, etc. are carried out. In digital pre-press, tasks focus on image digitisation, text processing, digitisation of originals where required, collation, assembly of digital publications, layout, etc. In short, it is a stage for optimising and preparing the print job, taking into account resolutions, dimensions, format, content and media.

1.2. Print

The most common printing systems include: offset printing, rotogravure printing on rotary presses, flexographic printing on rotary presses, screen printing and digital printing. The equipment, techniques and substrates used differ for each system.

Digital printing differs from other techniques mainly in that it does not use a printing plate. In this respect, its low costs and printing speed are its main advantages.

There are various technologies that fall under the umbrella of digital printing, and each of these techniques differs according to the format used.

The very versatility of digital printing means it can be used on a range of substrates, such as paper, canvas, banners or vinyl. When it comes to banner printing, there are three main materials: frontlit banner, micro-perforated banner (also known as mesh), double-sided (blockout) banner and backlit banner.

1.3. Post-printing

Finishing plays a practical, functional and quality-related role in the printing process. Once printing is complete, the material must be die-cut, folded and varnished to prepare it for assembly.

For example, when printing book-style documents, post-printing finishes include binding, stitching, ring binding, creasing, perforating and half-cutting.

The term ‘special finishes’ in the context of graphic printing on paper refers to the following types of finishes: lamination, encapsulation, varnish, stamping, faux embossing, debossing, security ink, etc.

In digital printing for signage on canvas and banners, the finishes depend on how the material will be displayed. In any case, to achieve an excellent finish, three factors must be taken into account: the quality of the material, reinforcement of the edges, and the correct choice of eyelet type.

2. Large-format print finishes

In the visual communications sector, large-format printing of posters and advertising is a very common technique that delivers excellent results in terms of advertising materials. These are used by shops, shopping centres, trade fairs, festivals and events in general.

The most common substrates used in the industry are vinyl, canvas, flags, advertising billboards and large-format paper. It is important to assess the type of substrate and the technology to be used, taking into account production volumes and whether the piece is to be displayed outdoors or indoors.

2.1. The most common finishes in large-format printing

Cut to the bone

Once the banner has been printed, it needs to be cut to the selected size. This is commonly used at trade fairs and events, and is the most basic way of finishing the banner.

Perimeter reinforcement

This system is recommended for maximising tear resistance. The edge is reinforced either by folding the tarpaulin over or by using a strip of tape along the edge to increase the thickness where the fastening system (eyelets) will be fitted.

To attach this load-bearing tape, it is necessary to use high-frequency, hot-air, hot-wedge or ultrasonic welding techniques.

It is essential for all types of fastening; however, for very small tarpaulins intended for use over one or two days and which are not exposed to inclement weather, this option may be omitted.

Vainas

Also known as a ‘jaretón’, these are an alternative to eyelets. They are commonly used on banners or in indoor spaces. This reinforcement is created by folding the canvas material so that it can be sewn or heat-sealed. Once this fold has been made, a tube is inserted to secure it.

In indoor spaces, you may only need a tube at the top; for outdoor use, it is recommended that you use another tube at the bottom to provide rigidity.

One of the drawbacks of this technique is that, if stitching is used, the material suffers significantly from being constantly pierced, which affects its tensile strength. Visually, the stitching detracts from the canvas’s appearance, as it is highly visible against the image.

Securing the tarpaulin using eyelets

The use of eyelets ensures the tarpaulin is fitted correctly. Eyelets are necessary to protect the tarpaulin from the tension exerted between the support and the frame. Without this component, the tarpaulin would tear easily.

The choice of grommet will depend on the type of tarpaulin and its finish. To fit them, you need to use specialised machines to punch holes and attach the grommets.

Velcro and adhesives

They are another way of reinforcing the perimeter. Double-sided tape can be used to join the fabric on both the front and back sides.

Se recomienda para los talleres de impresión que no tengan equipos de soldadora o para aplicaciones como bastidores. En ocasiones se usa velcro adhesivo como ocurre en los pop-up o displays.

The graphic arts industry encompasses a comprehensive range of solutions for visual communication. It is an industry undergoing constant change, driven by the latest technology. Understanding the various processes gives us a comprehensive overview of the graphic arts and large-format signage.

At PLASTGrommet, we are manufacturers specialising in digital printing finishing solutions, driven by our commitment to quality.