Eurostar has released new photographs showing the transformation of its fleet.
The cross-Channel rail operator is deconstructing its older trains into an empty shell before refitting them with modern interiors, Wi-Fi and an on-board entertainment system.
UK travellers will be able to experience the upgraded carriages on trips from London to Paris, Brussels, the Alps and the south of France.
The trains, which are more than 20 years old, are being given the same "look and feel" as the brand new e320 fleet, which entered service in November 2015.
Eurostar marked the completion of its third refurbished train over the weekend by issuing behind-the-scenes images of the operation at the Lille depot of French rail operator SNCF.
The process for each train takes around six months and includes the installation of 30,000 new parts, 2,086 new lights and 100 digital screens.
Each train is 400 metres long and consists of two power cars, 16 passenger coaches and two bar buffets.
A Eurostar spokesman said: "As we continue to grow and expand, investment in our fleet, stations and our service is key to improving the travel experience for our customers.
"In addition to introducing our brand new e320 trains, we are also refurbishing our original trains to the same Pininfarina design as the new fleet.
"With each train completely rebuilt and equipped with wifi and onboard entertainment, passengers can enjoy a seamless journey and a stylish, comfortable environment in which to work or relax."
Eurostar is investing more than £1 billion in its fleet modernisation programme.
The company's results for the third quarter of last year showed that passenger numbers were down 10% to 2.6 million compared with the previous year, as demand was dampened by the terrorist attack in Nice last July.
But in the run-up to Christmas, the operator said it was experiencing its busiest-ever festive period, up 9% on 2015, as the weaker pound encouraged more shoppers from the continent to take a trip to London.