As Finland continued its slow recovery from World War II in the early 1950s, textile designer Armi Ratia seized the opportunity to bring hope and optimism to the country—in the form of brightly colored and boldly patterned fabrics and clothing. From the remnants of her husband Viljo’s oilcloth company, the couple launched Marimekko in 1951. Less than a decade later, Jackie Kennedy graced a December 1960 cover of Sports Illustrated in a pink Marimekko dress, and the company took off, gaining renown for its bright, modern, fashion-forward textiles and clothing.

Today, a visit to Marimekko’s 43,000-square-foot factory in Helsinki reveals that its printing process and emphasis on big, bold patterns—which continue to bring the company great success—have changed little over the years. “Screen printing is a tried-and-true old technology, and printing large, six-foot-long patterns is rare these days,” says Petri Juslin, manager of Marimekko’s artwork studio. “This, however, is what we are known and loved for and what we excel at.” While many of its competitors are outsourcing their manufacturing, Marimekko continues to keep its production right at home and at the heart of its business, printing more than a million yards of fabric each year.

1. Design

The magic starts in Marimekko’s artwork studio, a simple room dominated by a large table surrounded by six skilled employees—many trained as designers. These workers interpret drawings from contributing designers and convert them into patterns. Marimekko gives contributors carte blanche on how to present their ideas to the artwork team: Some paint, some draw, some design on computers.

“One designer, Erja Hirvi, even came in with real branches she had attached to a piece of paper with tape,” Juslin says. The result was Lumimarja, which became one of the company’s best-selling textiles.

Once a design is approved, the artwork studio team determines the necessary number of colors. Marimekko designs can have up to 12 colors, though overprinting layers of ink can create additional shades. More colors means more work—though pricing is based on material and possible treatments and not on the color quantities. “We don’t charge more for more-expensive-to-produce fabrics,” Juslin says. The most difficult pattern to date is Vattenblank, designed by Astrid Sylwan for Marimekko’s Fall 2011 collection. The textile resembles a contemporary painting and is a tour-de-force of the company’s printing know-how. Its gradient effects, overlapping colors, and the sheer size of the repeat make it more a work of art than an industrially produced product.

2. Color Selection

Next, the screens are made, and the designer chooses the color tones. In a room next to the printing machines, a locker with narrow drawers holds numerous pieces of neatly stacked, colorful fabrics. “For many designers, this room is a real source of inspiration,” says Anna-Kaisa Jaaksola, who guides artists in the selection process. “Even though designers can work via email and send in Pantone codes these days, many prefer to choose the colors from real samples.”

The recipe for each color is attached to its corresponding fabric swatch, and after the designer chooses the right combination, the recipes are sent to the color kitchen. Some colors, such as beige and gray tones, are more difficult to produce than others; turquoise is notorious for sticking poorly to fabrics. “We have our trade secrets that ensure that the colors work,” says Anu-Mari Salmi, the production manager.

The inks are stored in plastic wrap-covered buckets, which prevents a thick, top layer from forming. Each day, the color kitchen prepares hundreds of pounds of ink for the hues needed for the following day’s printing. “Thanks to having our own facilities, we can react quickly to sales,” Salmi says.

3. Printing

The Marimekko factory prints nearly 6,500 yards of fabric each day. The company typically purchases its material, usually cotton, in 2,200-to 5,500-yard rolls or pallets from Germany, Peru, Turkey, and the Baltic nations. Flat screen-printing makes it possible to divide repeats in sections and create large-size patterns, from 24 inches to several yards long. With new patterns, the team produces a small, 16-to-33-foot test run before the real printing begins. If the test is successful, employees bring in the 63-inch-wide, 24-to-63-inch-long silk-screening plates and place them on the main printing machine. Each color is printed through its own color-specific, stencil-like plate. The more complex the design and the more colors used, the more plates —and hands (up to four professionals at a time)—are required to run the 80-foot-long printer.

With the screen-printing plates in place, workers spread the inks across the plates by hand. No computers are needed to determine the right quantity. “We trust our professionals,” Salmi says. “They have the know-how in their hands.” A metal rod guided by magnets, which can be adjusted for speed and weight according to the thickness of the fabric, presses the ink through the screen into the fabric. Once the ink is applied and the plate removed, the fabric moves forward automatically, and the next color is added through the next plate.

4. Finishing and Shipping

After printing, the fabric is transferred to the steaming machine, where steam heated to 219 degrees Fahrenheit fastens the color to the fabric, ensuring durability and brightness. Next, the textiles go through washing in 203-degree water to shrink them down to their final sizes. A finishing machine applies any additional treatments, like softener, to the washed fabric.

Then, Marimekko’s quality inspectors, some who have worked at the company for more than 30 years, hand-inspect and grade the fabric. Theirs is a meticulous task: There can be only four small errors over 16 yards of fabric. If the fabric passes, it is cut and rolled into bolts, ready for displaying in stores or turning into garments, bags, cushions, tablecloths, and other Marimekko products.

Finally, trucks are packed with yards of colorful fabrics—from the iconic Unikko print to those like the blossomed Keisarinna. The trucks drive to shops and ports and eventually transport the textiles to customers around the world.