No, the ability of the outdoor sign to maintain and last has nothing to do whether the printing was done solvent (oil based) or UV (oligomers/monomers).
The mechanism that will make it last or not last is the pigment portion of either ink formula. Depending on the degree of 'lightfastness' you are seeking, proper pigment selections can be utilized to maintain the print from fading.
If you are printing four color process build, generally here is how the lightfastness of each holds up.
Black> Black has infinite lightfastness, although improper choice of the blue toning element could fade. The carbon pigment is the armor that maintains here.
Cyan> Unlimited lightfastness using phthalocyanine blue pigment.
Magenta> Only fair lightfastness, when using the typical lithol rubine 57:1 pigment. 48 hour lightfastness is the usual reference.
What does 48 hours mean? That is the time the print would not fade in either a xenon or carbon arc fadeometer in a laboratory setting. Fadeometers are common pieces of equipment employed by ink manufacturers / formulators to check lightfastness or sometimes called fade resistance. Further, 24 hours is equivalent to a print being in direct sunlight at the Washington monument in the month of July and having the abilty to stand up and not fade for 30 days.
So as one can see, the end use and expectations for an ink printed with magenta is very important.
Yellow> The yellow is generally the most fugitive of the four colors. Pigment 12, Benzidine yellow will normally begin to fade at the 12 hour point.
With all this said, there is no need to fret. There are pigments that can be used for any color that will stand up to your end use requirements.
I want to give you an example where improper planning of ink choice takes place. Go to a Chinese carry out restaurant and the overhead menu with different offerings are often shown. Have you ever see that blue broccoli? That is because the yellow has faded out and now you have mostly only the cyan remaining. This is but one example.
Most important; always check with your qualified ink supplier to recommend and supply you with the proper ink (UV or solvent, as mentioned, does not matter) to meet your end use requirements. You want your printing to hold up for its intended life cycle, to avoid situations like the blue broccoli syndrome.
I hope this has been informative and helpful.
D Ink Man
