The Lunaire case study: a phone case

Third and last print-on-demand case study before the series turns an idea into a product. A second product from Lunaire: a phone case, personalised by colour choice rather than by birth data.

Why a phone case

The phone case is the most accessible thing a small personalised brand can sell. It sits under €40, which puts it inside gift-buying distance for most of the people who would not spend €89 on the embroidered Lunaire hoodie. The back of a phone is also one of the most-seen surfaces in daily life: by the owner, and by everyone they hand the phone to. A small piece of design gets a lot of minutes on display.

A plain phone case is a commodity. Buyers have no real reason to choose Lunaire over Amazon or a supermarket aisle. Personalisation is what changes that. The case is not sold as a Lunaire design. It is sold as your design, finished by Lunaire. A buyer spends thirty seconds to a minute picking colours, and the product arrives feeling like something they made, not something they chose off a grid.

As with the personalised hoodie in episode 5B, the case sits outside the standard EU 14-day return window. No returns on custom-designed goods is part of what makes this price and margin work.

The concept

Buyers pick two to four swatches from a fixed palette: black, grey, neon green, and a transparent option. The colours pool together as a fluid dye pattern covering the whole back of the case, as if the inks had been poured in and left to bleed. The transparent swatch is not a colour, it is the absence of one. Picked, it cuts random windows through the dye, letting the phone finish show through in pools as well as under the wordmark.

The word lunaire is the twist. Instead of printing the letters on top of the dye pattern, the letters are a transparent window in it. The case stays clear where LUNAIRE sits, so whatever the buyer’s phone is made of, titanium, aluminium, glass, rose gold, space black, becomes the colour of the wordmark. The shape and position of the letters never change. The finish showing through them changes from phone to phone. A standard print-on-demand service that prints on clear cases can produce this in one pass, no metallic ink required.

The palette is deliberately narrow, three colours and a transparent option. Every pattern is regenerated from a fresh seed, so two buyers picking the same swatches still walk out with different cases.

Decide the direction first

A phone case is the easiest-looking product in a catalogue and one of the fiddliest to run well. A few things to settle before building:

• How many phone models do you support? Every new phone release adds a product to the catalogue. iPhone alone currently covers more than a dozen live models. Android doubles the count.
• What happens when a buyer regrets their choice? EU rules place personalised goods outside the standard 14-day return window, so the buyer owns that regret, not the shop. The work shifts upstream: the picker and the product page have to make the choice feel considered, so regret does not surface in the first place.

Here is the generator.

The colour picker

The LUNAIRE wordmark is a transparent window in the dye pattern, not ink on top. The case is clear where the letters sit, and the phone’s own finish shows through them. Pick a case size, a phone finish to preview behind the letters, and two to four swatches. Generate new pattern reshuffles how the colours pool. The wordmark stays locked at the bottom, the same shape on every size.

The two Lunaire products, side by side

What to be aware of

• Colour on a small glossy surface reads differently than on a screen. Neon green in particular reads sharper on a printed phone case than it does on a laptop, especially under daylight. A physical proof is worth ordering before the palette is fixed.
• Wordmark placement needs to survive every phone shape. The back of an iPhone 15 Pro Max is a different canvas from the back of an iPhone SE. The rule for where the wordmark sits has to hold across all of them, not be hand-tuned per model. Bottom-aligned, sized as a fixed fraction of the case width, is the rule the preview above uses.
• The phone’s own finish is the wordmark’s colour. Titanium, glass, aluminium, rose gold, space black, whatever the buyer’s phone happens to be becomes the letter colour. This is the whole point of the knockout, but it also means the product page cannot promise a specific metallic finish the buyer does not already own. Frame the page around your phone, your ink, rather than a shade the shop controls.
• Polycarbonate, not TPU, for the case material. Cheap TPU cases yellow visibly after a year or two of sunlight, which dulls the neon green and clouds the knockout. Polycarbonate stays clear. Every major print-on-demand service offers PC clear cases; it is worth insisting on at the setup stage rather than accepting whichever material is cheapest.
• Two or three swatches usually compose better than four. The picker allows up to four including the transparent option, but a tighter pour often reads cleaner than a busy one. The picker does not enforce a taste rule; the product photography has to show the nicer end of the range.
• Provider choice is still open. The embroidery side of Lunaire assumed Printful. A phone case at this price and this colour palette is worth benchmarking across providers first. The next post is that benchmark.

What’s next in the series

• Comparing print-on-demand providers. Two case studies are now on the table, with different formats (poster, apparel, phone case) and different price points. The next post picks a provider for each using one common framework.

Subscribe below for the next one.