Large format outdoor prints require special and highly resistant substrates. One of them is Blue Back Side (BBS) paper.
Outdoor advertisements are exposed to changing and unfavorable weather conditions, which can quickly reduce their quality and also significantly affect the shortening of their service life. A number of techniques and treatments are used in printing to increase the durability of such prints and protect them from faster wear and tear. Thus, outdoor advertising uses special inks and printers, as well as papers.
It is a durable coated paper, opaque, of optimum whiteness and with a characteristic blue insulating undercoat, to which it owes its name. It is this backing that distinguishes BBS from other papers for large format printing. The blue adhesive-coated layer facilitates mounting and isolates the printout from the substrate on which it is placed. This further increases the durability of the advertisement and protects it from the adverse effects of external factors.
Blueback is available in several thicknesses – the most common is 115 gsm and 120 gsm, but you can also find thicker and thinner variants. It is usually sold in rolls with a specific width of the printing area (123 cm), but non-standard sizes can easily be ordered.
BlueBack paper is characterized by high resistance to temperature and humidity changes, direct sunlight, water and wind, and the durability of image colors is achieved through high-quality inks based on solvent dyes. In addition, it has virtually no tendency to crack or swell.
The life of BlueBack paper outdoors is limited to three months. If used indoors, it can serve for a whole year, maintaining the quality and freshness of colors.
Among the disadvantages, the only thing to point out is that it is not compatible with all types of printing presses, which means that not every ad manufacturer can print a high-quality image on it. For example, when printing on Blueback paper on an eco-solvent printer, the ink will not fully bond to the surface and will mostly just fall off. As a result, the resulting image will be pale and “snowy”.
UV printing is ideal for printing on blueback paper. The ink does not penetrate the paper, but instead stays on the surface, curing under UV light. The result is prints that are bright, clear and 100% environmentally friendly.
BlueBack paper is designed primarily for printing with solvent inks, but is also compatible with UV and latex inks.
Thanks to properties such as resistance to temperature fluctuations, wind, water and UV rays, it is most often used in outdoor advertising, especially for banners, billboards and various signage. BBS is opaque, so it can be applied to dark surfaces as well as other prints without tearing them off.
Since printing on Blueback paper is not very expensive, various companies, organizations, and activists running their own short to medium term campaigns are keen to use it.
Main photo: Annie Spratt/unsplash.com
