What’s the Difference Between Waterproof Labels and Weatherproof Labels?
What’s better for your business – waterproof labels or weatherproof labels?
These two label categories have a lot in common, but they’re designed for different purposes. A waterproof sticker can withstand moisture exposure, while a weatherproof label is designed to handle a range of environmental hazards, including UV light exposure and extreme temperatures. Weatherproof label materials aren’t always waterproof but have multiple protective properties to help them survive the elements.
How do you know which type of product label is right for you? We’ve broken down the properties of these labels, so you know what’s best for your small business.
The Basics on Different Types of Labels
Before you get started, it’s important to know the nuances of various labels. Let’s take a quick look at three common types: water-resistant, waterproof and weatherproof.
Water-Resistant Labels
Water-resistant labels are designed to withstand brief exposure to moisture. These labels are usually made by applying a waterproof coating on top of standard adhesive label stock.
Long-term exposure to moisture will allow water to seep into the stock along the edges of the label. Extended moisture can also cause smudging, ruining shipping labels and barcodes.
Waterproof Label Options
Every part of a waterproof label is waterproof, from the permanent adhesive to the top coat, allowing it to resist long-term exposure without peeling or smudging. Custom waterproof labels are used on products that might be submerged in water or stored in a wet environment. Common examples include water bottle labels.
Weatherproof Labels
Just like the name implies, weatherproof labels are designed to withstand a wide variety of conditions, helping with peace of mind if your product is exposed to the elements. After all, you don’t want these types of labels to be removable at the drop of a hat!
Unlike waterproof labels, weatherproof options of any label size require abrasion-resistant materials, ink that can withstand UV exposure and superior label adhesion (permanent adhesives are often used for this).
UV-Resistant Weatherproof Labels
If your label design will be exposed to the sun for more than a few simple business days, you’ll likely need to invest in UV-resistant weatherproof labels.
While fluorescent lights can cause fading, sunlight is a much bigger issue. A full-color label exposed to the sun for a long enough period can turn into a white, blank label if you don’t use the right label materials. This is a concern for outdoor products. Fading protection is also useful for products that might be stored near windows.
UV resistance comes from specialized inks used in label printing. Inks and dyes made for inkjet printers are usually tested with a xenon or carbon arc lamp, which simulates exposure to sunlight. These tests have to have strict temperature and humidity controls, since both can have a major effect on colorfastness. Simulating sunlight this way cuts testing time down from months to weeks.
Fading measurements are based on the Blue Wool scale. Although originally developed for textiles, this scale has made its way into testing for other materials. The first tests compared a sample stored in a dark area against a sample exposed to sunlight over 6 months. The material is rated on a 1-8 scale, with a rating of 1 for material that fades in a matter of days and 8 for material that shows no fade at the end of the test.
ASTM has several standards for testing lightfastness based on the Blue Wool Scale, with each test method designed for a specific material or application. The most applicable test for labels is D3424, “Standard Test Methods for Evaluating the Relative Lightfastness and Weatherability of Printed Matter.” This test includes aging methods using natural sunlight, xenon lamps, carbon arc lamps and fluorescent bulbs, making it easy to compare results. To get UV-resistant labels, you want to buy ink that’s been tested through these methods for your laser printer.
Temperature Resistant Weatherproof Labels
Most temperature issues are caused by adhesives. Low temperatures make adhesives brittle, breaking the bond between the label and the container surface. High temperatures melt adhesives, breaking their structure and their attachment to the container surface, allowing the label to slide off the container.
Cold-temperature adhesives can be divided into three grades. Freezer-grade adhesives are made to withstand cold and moisture, making them ideal for frozen foods. Cold-temperature adhesives can withstand temperatures well below zero, but they aren’t always moisture-resistant. Cryogenic labels handle extreme cold, including freezing in liquid nitrogen. Most adhesives in these categories are rubber-based, but not all rubber-based adhesives offer good low-temperature performance.
While high temperatures are an issue for containers that are heated by the consumer or stored in a car, most high-temperature adhesive tests focus on hot filling. In this process, foods are heated in the container to kill off pathogens, extending shelf life. Being able to use pre-labeled containers simplifies the packaging process.
The effectiveness of adhesives at these temperatures is measured with a Shear Adhesion Failure Temperature (SAFT) test. This uses a device that pulls on the label once it’s heated to see how easily it peels off.
Service Life of a Label
Even the most durable labels eventually fail over time. If you’re packaging materials that fall under HazCom regulations, the warning label must be readable during the entire life of the product. This might include years of outdoor storage.
Service life shouldn’t be confused with shelf life. Vinyl and polyester labels with high-quality top coatings are usually the best performers for long-term use. If you don’t need maximum water protection, paper is also a great choice.
Get the Equipment You Need for Fast, Accurate Labeling
CTM Labeling Systems makes pressure-sensitive labelers for nearly every application. If you need a better labeling solution for your waterproof labels or weatherproof labels, contact us and we’ll connect you with your expert local distributor. They’ll help you find the right setup for your production environment while ensuring fast, accurate labeling on your products.
