Solvent and Eco-solvent is a commonly used term when it comes to flex and vinyl printing. Eco solvent is a printing mechanism which is ecologically safe and used mainly for indoor applications. Normally solvent ink are harsh and are associated with definite odor i.e. Smell making them less likely to be used indoor.
Eco-solvent printing doesn’t have any harmful ingredients and it is biodegradable. Being biodegradable means it can break down and absorb in the human body without any complications. You need not take without any smell to be automatically labelled as Eco-solvent. Odor is just one of the advantage of the Eco material but there are lot many more as well. One definite advantage which we can associate with the solvent printing is that it can be used to print on wide variety or material. It is cheaper to print on this media.
They do exhumes fumes and it can be harmful to human. Outdoor banner or hoarding though is bigger but it is at such a height and distance that damage is very much limited.
Eco solvent media is a high resolution print where printing cost is more. Design artwork and images required should be high in resolution with no pixelation. We can expect very high quality print which is not the case with the solvent media. This is advised to used on good quality media which absorb the color well.
We use eco media mainly for indoor environment though it can be used for outdoor as well. As solvent type is made to last under outdoor weather condition, there is hardly any major issue. We use them for hoarding, banner, shop board, canopy, standees etc. All store indoor branding, POP displays, merchandise branding on the other hand is done on eco solvent.
From design perspective you have to ensure that there is high level of detailing, color profiling and better image resolution. On the other hand outdoor media like hoarding etc are made to be seen from a distance we can use large image and font size. This will make it more readable. Far distance viewing will make no pixelation visible from a distance. Big MNC and corporate design team often provide the artwork in high resolution preferably vector format where ever possible apart from embedded images, so that printers can adjust the resolution as required for these 2 types of media.
You would have also heard of 3 pass, 4 pass, 5 pass, 7 pass etc for flex printing. Pass printing means how many time print head will move over the media.
Higher the pass more pronounced should be the impression. More the number of pass will not make low resolution image print better. Eco solvent printing machine typically do not have any pass they are printed in high resolution with single pass only.
There is also common query whether flex is solvent and vinyl is Eco-solvent. Its a myth, flex and vinyl are the print media, whereas solvent and Eco is the ink. We can print both flex and vinyl through either solvent or Eco. Though it is preferable to go with better media for Eco-printing.