If you’re an avid plane spotter, you might have noticed something rather unusual about those tubes traversing the sky – a huge portion of them are painted white. Sometimes they’ll have a vertical stabilizer of a different color or boast a different colored belly or wing. Overall, though, there are an awful lot of pale planes taking to the air.

Why exactly is this? Is it purely aesthetic, or is there something a little more scientific to this choice?

According to Boeing, there are three main factors at play when an airline decides on a livery – cost, marketing, and environmental concerns.

That Paint Job Costs a Pretty Penny

In the aviation industry – every penny counts. While figures vary, it’s estimated it costs $50,000 – $200,000 to paint an aircraft in the most basic of liveries, and more for something complex. The paint doesn’t last forever, either. Southwest, for example, repaints each of their 737 aircraft every eight years. While that airplane is being painted, it won’t be creating revenue by ferrying passengers around. Before the paint job begins, the aircraft often needs to be flown to special painting facilities, and then back afterward. For a 777 sized plane, that’s up to two weeks of lost revenue for the airline.

Paint jobs for airlines are expensive because they are a fairly exact business. As noted by Adel Al Redha, Executive Vice President at Emirates, the aircraft has to withstand severe weather conditions – both hot and cold – and maintain an exterior coat that is free of imperfections, improving aerodynamics and fuel consumption. There is a lot of work involved, too. Sanding and stripping take place first – on modern aircraft, using a liquid stripping agent – then cleaning and priming. Following this, a base coat and numerous topcoats are applied, then a clear coat.

Of course, airlines are always looking for ways to save a dollar or two – and experimenting with different designs and paints is one way to do this. In 2011, EasyJet announced that it would utilize a paint that could be applied in thinner layers, allowing greater fuel savings and reducing drag. While this was announced in a great buzz of publicity, information on the results are a little less easy to locate.

Marketing Matters

Having a unique livery, as well as identifiable branding, is an obvious way to market an airline. Airplanes are effectively flying billboards. It would be a rare advertising executive that didn’t recognize the value of monopolizing on this utilizable space. However, with the rise of the ‘Eurowhite’ livery, we’ve largely seen a shift away from bold colors and brash patterns adorning aircraft. So, how do airlines differentiate themselves when they’re awash in a sea of similarity?

A shift to simple design elements seems to have been en vogue over the past few years, helped along by the sleek, minimalist design prowess of companies like Apple. This ultimate simplification of design elements associated with airlines has meant more large logos, distinctive fonts, and a focus on incorporating color rather than multiple graphic elements. These can all be addressed in a Eurowhite style livery, with enough differentiation for that all-important brand recognition.

Virgin Atlantic, for example, is using a special painting technique called ‘Andaro’. Though this is not a cheaper (or weight wise, lighter) option, its usage in specific areas of its aircraft – wingtips, engine covers and vertical – allows a rich, gleaming finish that shimmers in the sun. They’re still essentially branded as a Euro white, but there’s just that little element of differentiation for customers to recognize – a beautiful red color pop.

It’s for the Environment!

Or so they say. It’s more likely that it’s the aforementioned cost that drives airlines to make ‘environmentally friendly’ choices around paint jobs. However, there are a few cases where airlines do appear to be making positive choices for the environment, at least in the context of running gas-guzzling sky-birds.

Air New Zealand was one of the first airlines to benefit from the Boeing Environmental Programme, which used chromate-free primer in the painting process, helping reduce the environmental impact of paint and subsequent health and safety issues from paint usage. In turn, when it comes to repainting and touch-ups, it reduces the need for designated off-site disposal sites for paint waste. KLM use a paint that is applied in more but thinner layers, allowing a reduction of 15% in overall paint weight, and can be washed without harmful solvents.

Our feathered friends have a little bit of a say in the matter, too. A 2011 study indicated that, from the perspective of the avian vision system, white planes stand out more clearly. Given that an estimated $600M of damage is caused to planes by birds yearly, you can see that this would work in favor of both parties.

Every Cent Counts

One of the main reasons for the rise of the ‘Eurowhite’ phenomenon is the cost of aircraft liveries. As margins in the airline industry continue to get thinner, there is a need to account for every dollar spent. The fact of the matter is – simple paint jobs cost less to maintain, and lighter coolers are generally better for heat control.

While differently colored paints, in theory, weigh the same, it’s the potential number of layers needed to provide an opaque dark paint job that can add extra weight to the airframe. This means more fuel is spent simply, for example, getting the plane airborne, due to added weight. White paint reflects heat, meaning that it’s easier to keep the aircraft cool. This helps airlines manage the cost of cooling the airplane cabin, but also protects bits of the plane that are susceptible to heat damage. It’s also much easier to spot cracking or damage to a white fuselage then, say, an extremely busy paint job.

In the air, planes tend to fly high above cloud cover once they are at altitude, and are therefore exposed to direct UV radiation from the sun. White paintwork can help deflect this. It’s also reportedly far easier to on-sell a largely white plane, given it can be easily rebranded at a minimal cost.

Why Not Leave Them Unpainted?

My earlier comment on aesthetics? Sometimes, they do matter – or at least have a secondary purpose. When Concorde was still flying, it had to be painted with a very specific reflective white paint coating to be able to take the heat of supersonic travel. The Concorde could reach 260°F at the nose and trailing edge, but this special paint helped to reflect and radiate heat.

In 2006, Air Canada experimented with flying a fully bare 767 for three months, hoping to make fuel savings. The experiment didn’t result in any changes to the Air Canada fleet, with customers largely responding negatively to the new design. Polished aircraft only look good when it is continually, well, polished. This can cost up to $82,000 extra per year compared to painted planes, which far outweighed the supposed fuel cost savings of $24,000 for the Air Canada 767.

Today, you’re less likely to see bare aluminum designs. Although a few airlines, such as American Airlines, still fly some airplanes with a “bare chest”, they’re becoming less common due to more aircraft being made from composites such as carbon fiber. Besides, paint does add a protective barrier that can help the aircraft exterior resist premature damage.

And if you’re wondering why some aircraft host different colored bellies, it’s apparently to hide the dirt, oil, and slush that the aircraft picks up in daily operations.

Does This Mean Creativity Is Doomed?

Not necessarily. Like aircraft themselves, we will likely see advancements in the paint processes and pigmentations used in aviation painting. They’ll likely become lighter in terms of weight, and will hopefully offer greater reflectivity to UV rays, helping them to avoid fading for longer.

While we can’t tell exactly what the future will bring, airlines will still seek ways to differentiate their liveries – even if only temporarily. Let’s face it – EVA Air isn’t going to be getting rid of that lucrative Hello Kitty Plane anytime soon.