How to Tag Liquids, Metals, and Small Items for Walmart’s RFID Mandate

From liquids and metals to small items, some products are inherently harder to tag than others. Impinj-powered RAIN RFID technology delivers reliable performance across challenging surfaces, helping suppliers meet Walmart’s mandate and unlock operational efficiency. Walmart has required many of its suppliers to use RFID for more than five years. The mandate began with apparel in 2020, then expanded in 2022 to home goods, electronics, toys, and other categories. Now attention is turning to what’s coming next: cosmetics, cleaning supplies, and personal care products are expected to be included in future waves of the mandate. These new categories introduce unique challenges. Products that contain liquids, are packaged in metals, or that come in very small sizes can interfere with RFID performance and make RFID tags harder to read. That means suppliers will need to think carefully about how and where they place tags on their products – and many will be navigating RFID for the first time. For suppliers, the path forward starts with a clear framework: Step 1: Follow Walmart and ARC guidelines. ARC certification defines the baseline for compliance and maps your product categories with Walmart approved RFID tags. Step 2: Build a foundation of RFID knowledge. Understanding how RFID tagging works – and how packaging can affect it – helps suppliers ask the right questions. Step 3: Understand your product requirements. Products with hard to read surfaces like liquids, metals, and small form factors, each require different tagging strategies Step 4: Work with experts. Partnering with Impinj and our ecosystem of RFID tagging providers ensures compliance and reliable performance in real-world conditions. This Q&A is designed to help you build a strong foundation in what RFID is, understand what to consider for your product requirements, and learn how the industry – including Walmart, ARC, and partners like Impinj – work together to support suppliers. Questions Walmart CPG Suppliers Should Address Q1: What is a RAIN RFID Tag, and what’s inside? To choose the right tags, suppliers first need to understand how they work. The layers inside a tag determine performance, especially on hard-to-read products like liquids, metals, or small items. RAIN RFID Tag: The label you see and apply to a product. It can look like a sticker, hangtag, or fabric label and often includes printed text, graphics, or a barcode. RFID Inlay: The core technology layer inside the tag, consisting of an antenna and endpoint IC (sometimes referred to as a tag chip). This is the engine that enables RAIN RFID functionality. Endpoint IC: The “brain” of the inlay. This tiny tag chip drives sensitivity, read range, and determines how well the tag performs across different surfaces and packaging. In short: Tag is what you attach to a product, inlays are the technology inside, and the endpoint IC is what makes the whole system work.  Once you understand the layers inside a tag, it becomes clearer why product packaging — and especially “hard-to-read” surfaces like liquids, metals, or small form factors — can affect performance. Q2: What makes a product “hard to read”? Products with hard-to-read surfaces are items whose packaging and/or contents interfere with RAIN RFID readability. Common examples include: Liquids such as personal care products, beverages, and cleaning products that absorb RF energy. Metals like canned goods, aerosol cans, and foil packaging that reflect RF signals. Small items, including cosmetics, travel-sized items, and bottle caps, that provide limited surface area for a tag. For many CPG suppliers, these products sit at the heart of the product mix. Solving for reliable reads prevents downstream compliance and performance issues without disrupting packaging or branding. Q3: How do I choose the best tags for my products? Think of tag selection as finding the right tool for the job. The process starts with ARC-certified inlays that meet Walmart’s required specs – this ensures compliance. From there, suppliers should evaluate: Product and packaging needs: What’s being tagged matters. Liquids, metals, and small items may need compact tags or special placement. Work with your label provider: To help validate on real packaging by testing tag placement on your actual packaging to ensure consistent results in real-world settings. Build on performance: High-performance endpoint ICs enable smaller tags to pass ARC specs, improve read range, and broaden versatility across packaging type. Need help choosing the right tag? Check out the Walmart RFID Label Selection Guide for tips to simplify compliance and optimize your labeling strategy. Q4: What options exist for products with hard-to-read surfaces? Suppliers should choose ARC-certified inlays powered by the highest-performance endpoint ICs designed to overcome challenging conditions. These inlays are available through leading label providers – see our guide here. Current standouts include:  Smallest inlays certified across all retail specs — flexible across products and categories Includes: Arizon AZ-MR8C (44x20), Avery Dennison AD Stealth (50x14.5) , Checkpoint Marin (48x15), Hana TX5015 (50x14.5), Tageos EOS-261 (44x20). Maximized coverage for common items — compact 42x16 mm inlays meet Walmart Specs O/R/Y2, covering 99% of items typically tagged Includes: Avery Dennison AD Miniweb FCC, Checkpoint Voltis M830, Hana BRAVA, Tageos EOS-241 Specialized inlays for challenging surfaces — designed for liquids, personal care, and other difficult products (Spec B2) Includes: Checkpoint GR-583 (43x13), Tageos EOS-233 (30x30) With Impinj M800-powered tags spanning multiple ARC certifications, you can be confident your tags will perform in real-world conditions – not just in testing labs. Work with Impinj to connect you with the qualified Inlay providers to find the right ARC-certified solution for your products and stay ahead of Walmart’s mandate. Q5: How important is the endpoint IC inside the tag? The endpoint IC determines how well a RAIN RFID tag performs on hard-to-read surfaces. Choosing the right IC ensures reliable, consistent reads – even on products like liquids, metals, and small items. The Impinj M800 series endpoint IC is widely adopted for retail because it: Enables compact tags - powers the smallest ARC-certified tags available today Delivers reliable reads - high sensitivity and features like Impinj Autotune V3 improve accuracy and read range on challenging surfaces Supports efficient manufacturing – innovations like Enduro V2 simplify production and enhance durability across different packaging materials Supports broad ARC-certification - giving flexibility across diverse SKUs Simply put, the endpoint IC is the foundation of performance. Choosing a high-performing IC to power an inlay helps suppliers deploy tags that work reliably at scale. Q6: Why should suppliers act now, even if their items aren’t yet in an RFID mandate? Waiting until a mandate includes your category could leave you scrambling to source tags, test placement, and deploy solutions under tight deadlines. Acting early not only reduces risk, but also positions suppliers to capture bigger benefits from RAIN RFID adoption. Suppliers who take a proactive approach today can: Stay ahead of mandates. Additional categories – including health, beauty, or food and beverage – are expected in future waves Avoid disruptions. Reliable reads prevent shipment delays, compliance issues, and strained retailer relationships Secure supply. Early engagement with inlay and partners ensures capacity when mandates expand Unlock competitive advantage. Suppliers who solve hard-to-read challenges first can win trust with retailers and get products on shelves faster. Future-proof operations. Building RFID capabilities now creates resilience and scalability across categories. Q7: Beyond compliance, what’s the upside of RAIN RFID? When tags perform reliably, RAIN RFID delivers value far beyond meeting retailer requirements. Suppliers can achieve: Inventory accuracy up to 99% in retail settings Fewer out-of-stocks thanks to real-time visibility Operational efficiency with automated reads and fewer errors Supply chain resilience with end-to-end visibility from factory to shelf Reliable performance across all products — including hard-to-read SKUs — scales these across your entire business. For examples of how CPG brands are turning mandates into strategic advantages, see our recent blog on RAIN RFID and operational value. Future-Proof Your RFID Strategy Meeting Walmart’s mandate is just the starting line. The real opportunity is building a tagging strategy that scales with your business. By choosing M800-powered, ARC-certified inlays, you’re not only checking today’s compliance box – you’re securing reliable performance across future categories, packaging types, and retail requirements. Don't wait until the next mandate forces a scramble. Engage with Impinj and our trusted inlay and tagging providers now to design a flexible, future-ready solution. With the right IC at the core, your tags will deliver consistent performance today and adaptability for tomorrow. Get Connected with Qualified Tagging Providers Today. Article tagged as: Blog, Inventory Management, Retail, Supply Chain & Logistics, Manufacturing, Omnichannel Fulfillment, Industry Trends Thursday, January 22, 2026 ABOUT THE AUTHOR Carl Brasek Senior Vice President, Silicon Sales Carl Brasek oversees Impinj’s initiative to drive worldwide RAIN RFID adoption across all kinds of industries. Sign Up for the latest Walmart news