What is Laser Demetalization Technology?
Laser demetalization technology is a high‑precision marking process that uses a focused laser beam to selectively remove the ultra‑thin metal layer (typically aluminium) from a holographic film, leaving clear, transparent areas on an otherwise shiny metalized background. Unlike printing (which adds ink on top), laser demetalization is a subtractive process – it vaporises the metal without damaging the underlying plastic substrate. This creates permanent, high‑contrast marks such as serial numbers, QR codes, Data Matrix codes, microtext, and transparent windows. The resulting marks are extremely durable – they cannot be scratched off, washed away, or chemically removed without destroying the hologram. Laser demetalization is widely used for pharmaceutical serialisation, track‑and‑trace codes, high‑security authentication, and premium brand protection. Holoseal offers laser‑demetalized hologram labels with custom variable data, ensuring permanent, tamper‑evident codes that survive harsh environments.
🔬 How Laser Demetalization Technology Works
The process uses a pulsed laser (typically a fiber laser or diode‑pumped solid‑state laser) with a wavelength that is strongly absorbed by the metal but passes through or does not damage the PET substrate. Common wavelengths are 1064 nm (infrared) for aluminium removal. Here is the step‑by‑step process:
1. Laser Setup
A roll or sheet of metalized holographic film is loaded into a laser marking system. The system includes a laser source, galvo scanners (for beam steering), and a focusing lens. The focal spot size is typically 20–100 microns.
2. Pattern Design
The desired code (text, barcode, QR code, logo, or microtext) is designed in software and converted into laser scan paths. Variable data (e.g., sequential serial numbers) can be programmed, allowing each label to receive a unique code.
3. Laser Ablation
The laser beam scans the hologram surface, vaporising the aluminium layer in the shape of the pattern. The energy is precisely tuned to remove the 30–50 nm metal layer without damaging the PET film underneath. The ablation process is dry and leaves no residue.
4. Quality Verification
An inline vision system may verify the contrast and readability of the demetalized code. Barcode verifiers ensure the codes meet ISO scan grade requirements.
📦 Types of Laser Demetalization Patterns
- Serial numbers (human‑readable) – Unique numbers (e.g., 000001, 000002) lasered in a clear font.
- 1D barcodes (Code 128, Code 39, EAN‑13) – Demetalized bars for warehouse and retail scanning.
- 2D QR codes / Data Matrix – High‑density codes for smartphone verification and track‑and‑trace.
- Microtext – Text as small as 0.2–0.5 mm, readable under magnification.
- Transparent windows – A completely clear area (e.g., a circle or brand logo shape) through which underlying packaging can be seen.
- Hidden patterns (covert features) – Demetalized text or symbols that are only visible under transmitted light (holding the label up to light).
🛡️ Advantages of Laser Demetalization over Printing
- Permanent and tamper‑proof – The mark is part of the hologram structure. It cannot be scratched off, washed off, or dissolved with solvents.
- High resolution – Laser spot sizes down to 20 µm enable fine microtext and intricate patterns.
- No consumables – No ink, ribbons, or chemicals. Environmentally cleaner.
- Variable data at high speed – Change serial numbers instantly between labels without stopping the machine.
- Dual visibility – The mark is visible in both reflected light (dark) and transmitted light (clear/bright). This dual visibility adds an extra authentication layer.
🔐 Laser Demetalization vs. Inkjet Printing on Holograms
| Aspect | Laser Demetalization | Inkjet Printing |
|---|---|---|
| Mark permanence — | Permanent – metal removed.— | Ink can be scratched or dissolved. |
| Contrast — | High – transparent on shiny background.— | Good, but may fade. |
| Substrate damage — | None – only metal removed.— | None – ink sits on surface. |
| Speed — | Moderate – slower than high‑volume printing.— | Fast. |
| Variable data capability — | Excellent – sequential/random codes per label.— | Excellent. |
| Cost per label (volume) — | ₹1–10 (depending on area and complexity).— | ₹0.50–2 (lower for simple codes). |
⚙️ Applications of Laser Demetalization in Security Holograms
- Pharmaceutical serialisation – Unique Data Matrix codes on medicine cartons for track‑and‑trace (permanent, cannot be removed).
- Electronics warranty seals – Laser‑demetalized QR codes that survive handling and environmental exposure.
- Automotive parts authentication – Permanent serial numbers on hologram labels for engine components and safety parts.
- Tax stamps (alcohol, tobacco) – Demetalized excise codes that are impossible to scrape off.
- High‑value brand protection – Microtext and hidden codes readable only under magnification.
- Passport and ID card overlays – Transparent windows or microtext created by demetalization of the holographic laminate.
🌍 Holoseal’s Laser Demetalization Capabilities
Holoseal does not operate laser demetalization systems in‑house. We partner with specialised converting facilities that use industrial fiber laser marking systems capable of roll‑to‑roll or sheet‑by‑sheet processing. We manage the entire process – from creating the custom hologram master to applying laser‑demetalized variable data on finished labels. Our 15+ years of experience ensure that laser parameters (power, speed, frequency) are optimised for clean, sharp demetalization without damaging the hologram’s diffractive structure. We serve clients across India and worldwide, delivering laser‑demetalized hologram labels with unique serial numbers, QR codes, and microtext.
❓ Frequently Asked Questions About Laser Demetalization
- Does laser demetalization damage the hologram’s rainbow effect? – Only in the areas where metal is removed. The remaining metalized areas retain the full rainbow effect. The contrast between shiny rainbow and clear demetalized text is visually striking.
- Is laser demetalization suitable for short runs (e.g., 1,000 labels)? – Yes – laser systems can handle short runs economically because there are no printing plates. Setup time is minimal. For very high volumes (millions), inkjet may be cheaper, but laser offers better durability.
- Can laser demetalization create coloured text on holograms? – No – the process removes metal, leaving clear film. The text appears as transparent (not coloured). If you need coloured text, you would print ink on top or use a coloured metalization process (e.g., gold).
- How durable is a laser‑demetalized code? – Extremely durable – it cannot be rubbed off, and most solvents do not affect it (the PET base is resistant). Abrasive scrubbing will damage the whole label, not just the code.
- Can I combine laser demetalization with UV printing on the same label? – Absolutely – we can demetalize a QR code and then overprint a UV‑fluorescent logo. This creates multi‑layer security.
- How to order laser‑demetalized hologram labels from Holoseal? – Specify your hologram design, the content to be demetalized (e.g., “serial numbers from 0001 to 5000” or “QR code with URL”), label size, and quantity. We will produce sample(s) for you to inspect the clear/dark contrast. Contact us for a quote.
