A window box answers a question no photograph can: what does the actual product look like, right now, in my hand? Window patching — gluing a transparent film over a die-cut opening — is how retail packaging does it.
How it's made
The box sheet is die-cut with an opening, then a film is glued behind it in the same pass (or a following one) on a window-patching machine. The film must be applied before folding, precisely aligned — which is why window boxes cost a bit more than solid ones and why opening shape should be finalized before dies are made.
Film options
- PET (polyester) — the standard: clear, stiff, food-safe grades available. Most common by far.
- PP (polypropylene) — slightly softer, often chosen for food contact flexibility.
- rPET — recycled content version, increasingly requested for eco claims.
- No film at all — an open window on a box holding a bagged product (tea, coffee) is the cheapest and most recyclable version. Very common.
Design rules that matter
1. The window shows the product's best angle — but remember customers also see the *inside* edges of the box through it. Specify the inside color of the box (usually white or matching brand color). 2. Rounded corners on the opening resist tearing; sharp corners start them. 3. Leave a film border of at least 5 mm for the glue flange. 4. For food, confirm the film grade and the glue used near the opening.
When a window pays for itself
Products judged by appearance — candles, baked goods, toys, gift sets, anything with visible craft. When the product is inside an opaque inner bag anyway, a window is decoration, and a printed image of the product may serve better at lower cost.
Window patching is standard equipment on our line — typically quoted as a small add-on per unit. If you send product dimensions and the face you want visible, we'll propose an opening shape that cuts cleanly and shows it off.
FAQ
Can the window be shaped like my logo?
Yes, within knife-making limits — shaped windows are a die-cut away. Very intricate shapes cost more in die complexity and can weaken the panel; simple bold shapes work best.
Is the window film recyclable with the box?
PET windows complicate recycling marginally; most guidance says remove the film where possible. Open (unfilmed) windows and paper-based films keep the package fully recyclable — worth considering if sustainability claims matter to you.