Images visited Random Generator to meet the masters of marbled headwear

Tim Petrohilos, owner of Random Generator, started out in screen printing ten years ago after feeling frustrated at seeing £40 T-shirts that “weren’t that good”. His original manual press was located in the bedroom that he shared with his brother Benji – “He was living under a carousel, basically,” laughs Tim. Having moved out of the bedroom and, eventually, into a commercial unit in Tottenham, north London – the company’s current home – Tim has built Random Generator into a thriving business whose order book is filled with work from repeat and new customers. However, that’s not the reason why Images has braved a journey on Southern Rail to pay him a visit. Inside the Random Generator print shop something a little bit different is brewing… within a large plastic bucket.

Enter the premises and the scene is instantly familiar, with a manual carousel dominating the print floor surrounded by all the usual paraphernalia of a commercial screen printing operation. However, the attention of everyone in the room is focused not on the carousel but on a large, black bucket balanced on a small table covered with old newspapers. A quick peek inside the bucket reveals that it is filled with a gloopy liquid. Contrary to first appearances, this otherwise unremarkable container is, in fact, a vital piece of equipment in Random Generator’s new, somewhat unusual and distinctly remarkable cap marbling operation.

The inks are floated on the size and gently swirled together to create a pattern

Floating ink

The new operation came about as a happy accident, Tim explains. “My friend has a company, and we print his T-shirts for him. At trade shows, they do gimmicky things that they give away. The first year he did it, we printed the T-shirts and my mate who does graffiti sprayed the shirts. The companies would come up and say, ‘I want my shop name on it’ and he’d spray the shop name and they’d get a personalised shirt. The year just gone though, he wasn’t available, so my friend was trying to think of things to do and he saw a clip of hydrographics [applying printed designs onto 3D items] on YouTube and said, ‘Can you do that?’”

Hydrographics, which is usually applied to objects such as alloy wheels or motorbike helmets and involves transferring film that is suspended on a liquid onto an object, wasn’t practical for a trade show because of the equipment needed. Marbling on the other hand was perfectly well-suited to decorating apparel on location and creates a similarly striking effect. This much simpler process involves floating ink on a water-based liquid, called a size; the object to be decorated is simply dipped in the size, which results in some of the floating ink adhering to its surface, creating a genuinely unique design.

Marbling is a very old process, explains Tim, but despite this, there’s little information on it, and even fewer people who are qualified to share advice on the techniques involved. “It’s been a bit of a learning curve,” he admits. “The first five years of screen printing, that was a steep learning curve. And I think that’s the same with marbling, there’s a lot to it. We’re trying different inks and looking at the play between the inks and the mix of the size.” The size is made by mixing seaweed extract powder and water; the one Tim is using in the black bucket is made from carrageenan, a red seaweed. Ideally, it’s made the day before marbling to allow the size time to settle and for all the bubbles to dissipate.

Tim rates Jacquard inks for cap marbling

Tim dips a cap in the size

Once dry, the inks are fully bonded to the fabric

The items to be dipped are then soaked in alum, also known as potassium aluminium phosphate. “Alum allows the inks to adhere to the fabric,” says Tim. “You soak everything in that for 20-30 minutes and then take it out and let it dry naturally or with a little bit of heat.” Once the size has settled and the alum has dried, it’s time for the inks. The inks need to float; Tim’s still experimenting at the moment, but rates the Jacquard brand currently for the brightness of its ink colours. The inks are dropped onto the surface of the size in lines or droplets, depending on what effect is being created, using a pipette. Inks that are too heavy and sink into the size are watered down and tried again. Once enough colour has been added to the surface of the size, a cocktail stick is used to slowly swirl it all together to create a pattern.

The hat that is to be decorated is placed on a mannequin head and then dipped steadily into the bucket and pulled back out again – it’s almost a rolling movement that Tim uses. The cap is then dipped into water to remove any excess size before being left to dry, either naturally or in a tunnel dryer. Once dry, the inks are fully bonded to the substrate. “We’ve scratch tested the inks and nothing comes off– they won’t wash off,” says Tim. “One of the reasons I’m confident about this is that when the caps are placed in the cold water after being dipped, we rub off the excess size with our hands and it doesn’t affect the pattern.”

All styles of headwear can be dipped

Once one cap has been dipped, the size can be reused – Tim simply drags a piece of newspaper across the top to absorb the leftover ink and then it’s ready for the next inks to be added. “Obviously, the more you use the size, the more contaminated it gets, but the bit that transfers onto the fabric will always be the ink at the top. Sometimes you’ll take a cap out and you’ll see a whole layer of ink that was just underneath the surface of the size sliding around the top of the cap – it moves around. But underneath, set solid, is the initial ink pattern that touched the fabric first. That bit will have adhered to the fabric, and the moving layer of excess size will wash off in the cold water.” The technique works on cottons, polyesters and even plastic size-adjusters. As long as it can be soaked in alum, it can be dyed using this technique.

Personalised and unique

The live marbling of the caps at the trade show, with people able to choose the colours they wanted, was a big hit. It’s hard to imagine a better time for Tim to decide to learn this technique – live printing is a growing area as more bricks-and-mortar shops try to find ways to increase footfall, while companies everywhere are looking for new ways to stand out from the crowd both online and in person. Cap marbling also offers a similar appeal to tie-dye, one of the hottest trends for 2019 – every piece is unique. “You can’t have two the same,” confirms Tim. “I’ve managed to get two that are really similar just by doing the same proportions and colours and a similar pattern – but they weren’t identical. They’ll never be identical. And people at events, they love that – it’s completely unique, no one else is going to have one like this. It’s their own thing.”