Almost every clear case on the market is a two-part build: a TPU frame that grips the phone and takes the drop, and a rigid clear back that keeps the outward face scratch-free. They are different materials doing different jobs, and the choice of back is where both the cost per model and the yellowing story get decided.
Three ways to build a clear case
We make all three. The table is the short version; the three sections under it are the parts that get left out of a quote.
| Build | Back panel | New moulds per model | Scratch | What ages |
|---|---|---|---|---|
| All-TPU | none — single shot | 1 (TPU) | Poor | The whole shell |
| TPU + acrylic back | acrylic, cut to outline | 1 (TPU); the back needs a cutting program, not a mould | Good | The frame only |
| TPU + hard-coated PC back | PC, moulded then hard-coated | 2 (TPU + PC) | Good once coated | The frame only |
All-TPU: softer, cheaper, and it yellows all over
One material, one mould, no seam. If you want the softest feel and the lowest tooling of the three, this is it.
The trade-off is that TPU is the material that yellows, and on an all-TPU case there is nothing to hide behind. It is not the edges that change colour — the entire shell does, because the entire shell is the same material. If your buyers return clear cases over yellowing, this is the build generating those returns.
TPU frame + acrylic back: one new mould per model, not two
This is what most of the market sells, and the reason is arithmetic rather than preference.
Every new phone model needs its own TPU frame tool. One mould serves one model, always — that cost does not go away with any build. What changes is the back. An acrylic back is cut to the model’s outline on a CNC or laser, so a new model costs a cutting program instead of a second mould. On a TPU + PC build, that same new model needs the second mould as well, because the PC back has to be injected.
One tool per model instead of two. That single sentence is most of the price difference between an acrylic build and a PC build.
TPU frame + hard-coated PC back: two moulds, and the coating has to survive the second shot
PC gives you a back with tighter dimensional control than cut acrylic, and once it is hard-coated it takes a scratch that would mark bare PC.
The cost is process. The PC back is moulded first, hard-coated second, then placed into the TPU tool as an insert and overmoulded. The coating is the whole reason for choosing PC, so it has to come through the injection cycle intact. Not every shop will run that sequence, and the ones that will quote a second tool for it.
What overmoulding does, and why the back has to be made first
Overmoulding is not gluing. The back panel goes into the TPU tool as an insert and TPU is injected around its edge. The finished part is one piece with a mechanical bond at the perimeter — not two parts held together by adhesive.
The order of operations is fixed: make the back, coat it if it is PC, then overmould. You cannot coat the back after the frame is on, because the frame covers the edge the coating needs to protect.
Three things decide whether that bond holds: where the insert sits in the tool, the melt temperature against the coating, and the radius at the corner. A back that sits a fraction off centre shows at the seam, and the corner radius is where a cheap overmould fails first — it lifts from the outside in.
Why a clear case turns yellow, and what does not
Only the TPU yellows
Acrylic and PC backs do not change colour. That is the practical argument for a two-part build: the frame ages, the back does not, and the case still reads as clear across the face where most of the surface is.
An all-TPU case has no such protection, because every square centimetre of it is the material that ages.
The grade sets the clock
Standard TPU turns visibly yellow in roughly three to six months of daily use. Bayer-grade TPU holds its clarity for roughly six to twelve. That is a material cost we pass through rather than a process trick, and it is the single biggest variable in how a clear case is judged six months after delivery.
What makes it worse
Sweat, UV and heat, roughly in that order. A phone carried in a pocket in a hot climate ages faster than the same shell on a desk. Body chemistry matters too — some people yellow a case in half the time, and no coating fixes that. If a buyer tells you their last clear case went yellow in two months, believe them; it is not a defective batch.
Frosted frame, clear back: hiding the ageing
One more build, aimed at markets where yellowing is a real objection: the frame is moulded in frosted TPU and the back stays clear. The frame still yellows — frosted TPU is still TPU — but the colour shift is far less visible on a matte surface than on a polished one.
We describe it that way on purpose. Frosted hides the ageing; it does not prevent it. A buyer expecting a frosted frame to stay optically clear for two years will be disappointed, and it is better to say so before the order than after it.
Printing on a clear shell
White ink goes down first
A clear case cannot be printed like a coloured one. Colour laid straight onto clear TPU reads as a tint, because light passes through it instead of reflecting off it. So a white base coat goes down first, then the colour, then a clear top coat.
That extra pass is why printing on clear costs more than printing on a solid shell, and why fine detail on clear needs a higher mesh count than the same artwork on an opaque part.
What survives on clear
UV printing holds gradients and photographic detail, but on clear it needs both the white base and a top coat to survive pocket abrasion. Screen printing gives the most durable result for solid colour and line work. IMD works on clear, but the film has to register to the window, and that tolerance is tighter than on an opaque part — expect a higher setup cost and a longer proof cycle.
MOQ, tooling and lead time
MOQ is 100 pieces per model. Colour matching on the frame carries its own minimum, which depends on the model — ask us and we will give you the number for yours.
The TPU frame follows the same schedule as any shell we cut: 5–7 days for the 3D drawing and DFM review, 10–15 days to cut the frame tool, then 5–15 days for the first batch. A TPU + PC build adds the second mould and the coating step, which moves both the cost and the calendar.
Prices sit in the same band as our other TPU shells. The four variables on the custom phone case page apply here unchanged, and we quote against your part rather than publishing a list — a clear case with a printed back and a plain one are not the same job.
When clear is the wrong choice
Three situations where we will point you elsewhere:
- You need the shell to stay optically clear for two years. No TPU does that. Take a hard PC shell and accept that you lose the soft grip and the drop absorption.
- You want soft-touch feel and zero yellowing in one part. Those two requirements do not coexist. Pick one.
- You are selling into a market that judges a case by its first month and your volume is small. A frosted frame hides the ageing; a polished clear frame will not, and at low volume you cannot absorb the returns.
FAQ
How much does a clear case cost compared with a solid one?
The same tooling and the same moulding time. The difference is printing: a clear shell needs a white base coat under the artwork, which is an extra pass. Plain clear with no print is the cheapest thing we make.
Can the frame and the back be different colours?
The back stays clear acrylic or PC. The frame can be colour-matched in TPU. A coloured frame with a clear back is a normal build here, not a special order.
Does the acrylic back come off?
No. It is overmoulded into the frame, not clipped and not glued. It is one part.
Will the frame yellow if the back does not?
Yes, and that is the honest answer for every clear case on the market. Only the TPU ages. Bayer-grade TPU buys you six to twelve months instead of three to six, which is why we quote both grades.
Can you match a Pantone reference on the frame?
Yes, on the TPU frame. The back is clear by definition. Ask us for the minimum quantity per colour on your model — it is set by the model, not by us.
Send us what you are making.
Model, quantity and the artwork you already have is enough to start. You get a price range and a lead time within one working day — no account, no ticket queue, no waiting for a form to be read.