Airlines are some of the most recognized brands in the world, and there's no better billboard for them than the fuselage of their own aircraft.
Once upon a time airline liveries were all about national flags. They were both a symbol of a country's pride and an expression of the quasi-diplomatic status airlines enjoyed (hence the term "flag carrier").
All this changed with the liberalization of the air travel industry.
The emergence of a dynamic and competitive private airline sector opened the floodgates of creativity when it comes to aircraft liveries: from the bright, eye-catching colors favored by low-cost carriers to the intricate one-off designs with which some airlines choose to delight aviation enthusiasts every now and then.
Cute animals, cartoon superheroes and artistic masterpieces -- everything is fair game when it comes to seeking the public's attention through a catchy airline livery.
Patriotic paint jobs have by no means gone out of fashion, either. In June 2020, UK Prime Minister Boris Johnson made the controversial decision to spend a reported £900,000 ($1,116,000) of taxpayers' money on a Union Jack-themed makeover of the prime ministerial RAF Voyager jet.
What does it take to paint an airliner?
As anyone who's been to an aircraft factory knows, all airliners are painted the same colors when they come out of the assembly line: green for metallic aircraft and beige for those made of composites (since there is no need of corrosion inhibitors).
The green is due to an initial layer of anti-corrosive zinc chromate coating. The first of several procedures the aircraft is going to go through until it gets its definitive color scheme.
After the airline has signed off the livery design, which has often been devised by an external creative agency, it works closely with the aircraft manufacturers to implement it.
Aircraft makers such as Airbus and Boeing have their own paint facilities and dedicated teams that step into the process at this point. They produce a dossier that details everything needed to complete the requested paint-job: the type of paint to be used, the patterns that are to be applied, the amount of resources that will be needed and so on.
A virtual computer-generated 3D model is then created.
This "virtual twin" of the real aircraft will then be used to produce stencils. These are large, adhesive, pieces of canvas that when laid out on the outside of the aircraft and sprayed with paint, produce the desired color patterns.
The aircraft is then ready to move onto the paint shop.
Every layer adds weight
First an eco-friendly chrome-free primer is applied. This is a preparatory coating that helps the adhesion of the successive layers of paint.
Next is a layer of background color, which is often white, but not always (it depends on the final color scheme).
It's on top of this background layer that the final color pattern is applied with the help of stencils.
The last layer is a clear coat applied after all the other colored paints and adhesive films are already in place. This varnish seals everything and provides robust protection against air flow erosion, all sorts of fluids and the effects of UV rays.
The thickness of these paint layers is very important, since each additional layer of paint adds weight to the aircraft. More weight means higher fuel consumption and this adds up over the operational life of the aircraft, with significant economic and environmental consequences.
This is why painting processes have been the focus of significant technical innovation, with modern low-pressure, high-volume spraying tools and techniques aimed at reducing the amount of paint required to paint an aircraft.
But it's not just new aircraft that visit the paint shop.
Time for a makeover
Commercial aircraft are re-painted several times throughout their operational lives. This way, airline liveries remain bright and crisp, and well maintained paint can also help prevent potential corrosion issues.
"Large airlines with hundreds of aircraft, such as United or Southwest, have a schedule to repaint their aircraft with certain regularity, usually every six years or so," explains Nikki Thomas, an executive at IAC, the world's largest independent aircraft painting company.
Firms such as IAC also take on contracts for major aircraft manufacturers when they need extra capacity that can't be fully handled by their own painting lines. Most of their business, however, comes from aircraft that are already in service.
Changes of ownership, airline re-brandings, mergers and acquisitions are also major drivers for the aircraft painting market.
"When two airlines decide to merge, it's a dream come true for us!" jokes Thomas, before adding, "Look for example, at United's new livery, which was unveiled in April 2019. This will mean that nearly 1,000 aircraft will need to be repainted."
In the case of aircraft that are already operational, it's essential to remove the current layers of paint first. In order to do this, the aircraft must be either sanded or stripped, the latter being a more thorough procedure involving the use of chemical agents that wash away the old paint.
The method of choice depends on the state of the aircraft when it arrives at the paint shop.
Time and money
Painting an aircraft usually takes around one to two weeks and the costs can vary greatly.
It all depends, of course, on the size of the aircraft and the complexity of the design.
For instance, painting a regular passenger plane costs somewhere in the region of $150,000 to $300,000, while the price for a smaller plane could be as little as $50,000.
However, the makeover of the UK's prime minister's RAF Voyager jet is thought to have cost over a million.
The Alaska Airlines Boeing 737 with a Disney-Pixar "Toy Story" livery took IAC a whole 21 days to complete. This was because the elaborate design involved fine details having to be finished off by artists with paintbrush in hand, rather than the more conventional spray.
Another faster, cheaper technique sometimes employed to decorate aircraft with particularly complex designs is the use of large special adhesives, called decals.
These are, essentially, stickers (although produced to particular industry specifications) that can be printed and then stuck at the right spot on the aircraft.
But decals aren't to everyone's taste. IAC rarely uses them, says Thomas. It prefers to stick (pun intended) to paint.
There can also be significant differences between different types of paint.
Some are not only more expensive, but considerably more difficult to apply than others, to the point that paint crews need to be given extra training. A case in point is that of liveries using pearlized mica paint.
Jean-François Paul, head of the Airbus paint center in Toulouse, France, gives the example of the livery on the Virgin Atlantic A350 aircraft, the first of which was delivered in the summer of 2019.
This livery uses special effect paint, which contains tiny aluminum particles and and other specific pigments that produce a unique glittering effect.
Although at first glance the design pattern looks rather straightforward, the way the different shades of red are laid out shows an unusual complexity and sophistication.
"This was a very challenging livery to make, but it is beautiful," he says.