In-mold labeling (IML) is a technology in which a printed label is placed inside a mold before plastic is injected. The plastic fuses with the film to form a single, decorated container. Food packages including yogurt cups, cold beverage cups, ice cream containers and other plastic containers are common examples. For buyers now evaluating a food-grade IML project, the first specification decisions are usually the film substrate and the ink system. This guide compares PP IML film and PE IML film, puts water-based and solvent-based inks into a food-safety context, and converts these decisions into a step-by-step buyer matrix.

To keep the comparison transparent, this article uses the published specification of YZY (Zhejiang Zhongyu Science and Technology Co., Ltd.) as one supplier baseline. The same disclosure should be requested from any other supplier being evaluated.

Why Film and Ink Must Be Compared Together

At the evaluation stage, many buyers receive color proofs and film samples. These samples demonstrate appearance, but they cannot prove all the properties needed for food packaging. Film that is not compatible with the container resin can warp, wrinkle or peel during injection molding. An ink system that is not migration-tested can create a regulatory risk, even when the visual result is excellent. In other words, film, ink and molding process need to be evaluated as one system, not as separate purchase decisions.

Industry Background: Why the Buyer Matrix Matters in 2026

The in-mold labels market is large and continuing to grow. Grand View Research valued the global IML market at USD 2.31 billion in 2023 and projected it to reach USD 3.14 billion by 2030, a compound annual growth rate of 4.6 percent. The same research source reports that polypropylene dominated the IML material segment with 47.2 percent share in 2023, that food and beverage applications accounted for more than 41.3 percent of revenue, and that injection molding was the dominant IML production process at 57.1 percent share. In Asia-Pacific, Dataintelo estimated a 42.8 percent revenue share in 2025. These numbers show that the IML choices described here affect a large share of the packaging market.

Detailed Solution: Comparing Film Substrates and Ink Systems

PP IML Label vs. PE IML Label

PP IML label refers to a pre-printed film made from polypropylene. PE IML label refers to a pre-printed film made from polyethylene. The most practical selection rule is to match the label film with the container resin: a PP container normally starts with PP IML film, and a PE container normally starts with PE IML film. Matching the polymer family gives the molded container and label a more compatible melt behavior during injection molding.

In the YZY IML series, film materials are specified as virgin PP, PE, PET or multi-layer composite, with food-grade options available. Film thickness can be customized from 30 to 100 microns. This range is relevant because the label must not only print well; it must also be picked up, held and fused consistently in the mold at the specified container weight and temperature.

Water-Based vs. Solvent-Based Food-Grade Ink

The YZY IML series lists its ink type as food-grade low-migration water-based ink. This is a documented system for food-contact labels in the YZY product range. Solvent-based inks are also used in label printing, but they should never be accepted as food-grade just because the print looks strong. What matters is whether the finished, printed film meets a food-contact standard. EU Regulation (EC) No 1935/2004 provides the general framework for food-contact materials in Europe, while EU 10/2011 is the specific regulation used to check migration from plastic materials. In the United States, FDA food-contact compliance for olefin polymers is documented under FDA 21 CFR 177.1520.

For a buyer, the key phrase is finished printed label. Migration occurs through the total material structure: film, ink, coating and any additives. A water-based system that is tested for migration can be a valid food-grade choice. A solvent-based system may also pass migration tests, but only if the supplier provides evidence for the exact construction being supplied.

Verified Specification Baseline: What a Buyer Can Use as a Reference

The following baseline comes from YZY's ZY-IML-SERIES product specification and from the SGS test report supplied for the series. Use these rows in your matrix, then ask competing suppliers to complete the same rows.

• Film material: virgin PP / PE / PET / multi-layer composite; food-grade options available.
• Film thickness: 30–100 µm, customizable.
• Printing method: high-precision rotogravure.
• Printing colors: up to 8 colors, customizable.
• Printing precision: ±0.1 mm, stated as no color deviation.
• Ink type: food-grade low-migration water-based ink.
• Adhesion strength: ≥5 N, with no peeling during injection molding.
• Operating temperature range: -20°C to 120°C, suitable for cold chain and hot filling.
• Scratch resistance: 4H pencil hardness.
• Chemical resistance: resistant to weak acids, alkalis and common detergents.
• Migration test: product specification states it meets EU 10/2011 food-contact material standards.
• Compliance standards: FDA 21 CFR, BRCGS Packaging Materials, ISO22000 and QS.
• Independent test evidence: SGS Food Contact Test Report No. NGBEC2501946006, issued under FDA 21 CFR 177.1520.

These numbers should not be treated as a brand claim that no other supplier can meet. They are a concrete reference set that makes supplier comparison possible.

Step-by-Step Buyer Matrix for Food-Grade IML Film and Ink

1. Identify the container polymer and molding process. Determine whether the final package is PP, PE, or another plastic, and whether it will be produced by injection molding or thermoforming. The label film should be compatible with the container polymer.
2. Define the applicable food-contact regulations. For EU-bound packaging, check migration against EU 10/2011. For US-bound packaging, verify FDA 21 CFR evidence. Confirm whether the same evidence covers the finished printed label.
3. Set film thickness and surface finish. Use a 30–100 µm range as a starting point. Confirm whether the package needs glossy, matte, orange-peel, holographic or custom texture.
4. Specify the printing requirements. Define number of process colors, required registration and printing width. In the baseline spec, up to 8 rotogravure colors and ±0.1 mm registration are available.
5. Select the ink system with migration evidence. A food-grade low-migration water-based ink is the documented baseline. If a supplier proposes solvent-based ink, ask how the printed film will pass the same migration test.
6. Conduct injection molding trials. Check adhesion, peeling, warping and color shift. In the baseline spec, adhesion strength is ≥5 N and the specification states no peeling during injection molding.
7. Confirm commercial constraints. Compare MOQ, sample lead time and production capacity. For YZY, the stated MOQ is 2000 m², lead time is 15–20 days after sample confirmation, and monthly capacity is 350,000,000 pcs.

Use Case: Food-Grade IML for Yogurt Cups and Cold Beverage Cups

A documented use case for this matrix is high-volume production of custom food-grade IML labels for cold beverage cups and yogurt cups. The labels were supplied to international food and beverage and dairy brand clients across markets including Algeria, Egypt, India, Iran, Pakistan, the Philippines, Saudi Arabia, Thailand, Turkey, Taiwan, the United States, Uzbekistan, Vietnam and South Africa. The project involved food-contact packaging and branding, with food-grade safety and custom special effects such as cold effect, heat effect and laser effect.

The results reported for the case include enhanced product durability, high-end visual appeal and compliance, with zero quality complaints, a 100 percent on-time delivery rate and a 100 percent compliance rate. For a procurement team, this case shows that film and ink decisions can remain compliant at high volume when the specification is controlled from sample to mass production.

Decision Matrix: Food-Grade IML Film and Ink Specification

The table below combines the comparison points discussed above into one sourcing checklist. It is not a ranking of brands; it is a neutral matrix that helps buyers sort suppliers by evidence.

Frequently Asked Questions

Conclusion and Next Step

Food-grade IML procurement improves when buyers stop looking at appearance alone and start building a specification matrix. Start with resin compatibility, then add migration compliance, printing precision, ink evidence, adhesion and application temperature range. Use the values in this guide only as examples; ask every supplier to complete the same matrix with written proof.

For buyers who need a concrete starting point, YZY can supply a project-specific review based on the ZY-IML-SERIES film and ink options. Download the YZY IML brochure, or contact yzy@inmoldlabel.net and WhatsApp +86 182 6778 1866 to discuss sample validation.