--- title: How to Print on Plastic Film Substrates With Flexo Printing date: 2026-02-06T03:00:00Z modified: 2026-08-16T07:59:25Z permalink: "https://www.zp-flexopress.com/blog/buying-guide/print-on-plastic-film-substrates-guide/" type: post status: publish excerpt: "" wpid: 965 categories: - buying-guide featured_image: "https://www.zp-flexopress.com/wp-content/uploads/2026/02/How-to-Print-on-Plastic-Film-Substrates-With-Flexo-Printing.webp" featured_image_alt: How to Print on Plastic Film Substrates With Flexo Printing timestamp: 2026-08-16T07:59:25Z tags: - buying-guide --- ## Quick Answer Printing on plastic film with flexography requires controlling six key factors: surface tension, surface energy, wettability, ink selection, distortion, and cost. Ink must have surface tension 10 dynes lower than the film’s surface energy for proper adhesion. Corona, chemical, or photochemical treatments boost surface energy. Choose surface or reverse printing based on durability needs. RAZP, a trusted manufacturer of CI and Stack flexo machines, achieves ±0.01 mm accuracy and reduces film waste by 10%. Printing on plastic is among the main processes in modern flexible packaging and industrial labeling. However, as plastic films are non-porous and often have [low surface energy](https://www.zp-flexopress.com/wp-content/uploads/wp-mfa-exports/post/ink-surface-tension-guide-flexopress-label-printers.md), achieving durable plastic prints requires precise control of ink adhesion and surface treatment. Flexographic technology provides consistent ink transfer, high speed, and mechanical control needed to address these adhesion issues. This guide explains the technical factors that influence plastic prints, including surface energy, wettability, ink selection, and flexo press configuration. ## **Understanding Plastic Substrate Printing Among the most well-known substrates nowadays are rigid vinyl PVC, polypropylene and/or BOPP, and polyester (PET). The benefits of these plastic substrates compared to traditional ones are their durability, resistance against water or chemicals, and are more cost-effective for many applications. Plastic substrates produce prints that are clear and vibrant, attracting more customers and increasing the sales of your business. [Flexographic printing](https://www.zp-flexopress.com/wp-content/uploads/wp-mfa-exports/post/understand-flexographic-printing-process.md) is one of the most foolproof methods in printing on plastic sheets. ## **6 Factors to Remember on How Print on Plastic Film** There are various factors to remember when printing on plastic film materials. ### 1. Surface Tension: Ensure the Ink Sticks Surface tension is the force in liquids that makes them behave as if they are covered by a thin, stretchy skin. This happens because the molecules in the liquid are attracted to each other, which is why liquids often form round droplets instead of spreading out. In printing, surface tension affects how well ink spreads across a surface measured in dynes per centimeter (dynes/cm). For proper printing, the ink must have lower surface tension than the image carrier to transfer smoothly. For instance, a plastic film at 40 dynes/cm needs ink at 30 dynes/cm or lower to ensure even spreading and clear prints. How to optimize: - Utilize an ink with a surface tension 10 dynes lower than the surface energy of the film. - Adjust the ink with additives like alcohol or use treated films to enhance compatibility. ![](https://www.zp-flexopress.com/wp-content/uploads/2026/02/How-to-Print-on-Plastic-Film-Substrates-With-Flexo-Printing1.webp) ### 2. Surface Energy: Make Sure the Ink Stay Out Surface energy is the surplus energy at the surface of the plastic substrate compared to its size, measured in joules/sq. meter. When selecting the type of plastic substrate for your end packaging to use for flexo printing, it is vital to know its surface energy. This prevents ending up with much expensive and time consuming printing defects. Most plastic substrates can be easily treated to increase their surface energy, ensuring it is higher than the ink’s. This allows the ink to properly adhere and transfer smoothly. ### 3. Wettability: Get Smooth Coverage This is the ability of ink to wet the surface on which you are printing, affected by the ink’s surface tension, the surface energy of the substrate, and/or the polar quality of your image carrier. In short, wettability affects how well your ink lays or spreads out on your surface. It is essential to have good ink-substrate interaction to make sure clean, defect-free prints when printing on plastics that are clear. This ensures a smoother coverage, less pinholes, and overall less printing defects. How to optimize: - Match the ink to the surface energy of the substrate. - Use highly polar plates and high-energy substrates to improve interaction. ### 4. Ink Selection: Choose the Accurate Ink Select inks with surface tension that is 10 dynes lower than the surface energy of the plastic film. This allows the image carrier to fall easier in between. You can adjust ink surface tension using additives like alcohol or other treatments. However, it’s usually easier and more effective to treat the plastic film instead. This ensures better wettability and consistent quality prints. | _Tip: Take a quick test for a small batch of prints to ensure the ink sticks well and the colors pop._ | | --- | ### 5. Distortion Control: Keeping the Images Sharp In flexo printing, images can sometimes stretch or distort because the printing plates are flexible. To prevent this, you can use durable [elastomer sleeves](https://www.zp-flexopress.com/wp-content/uploads/wp-mfa-exports/post/printing-cylinders-vs-sleeves.md) instead of standard plates. These sleeves are designed to keep their exact size, helping prints stay sharp and accurate. They are also more durable, so they last longer and can be used for more print runs without wearing out. ### 6. Time and Money In large-scale industrial printing, efficiency is key to maximizing profits. Proper calculations are essential to avoid redoing steps due to sizing errors. With a well-made elastomer sleeve, achieving accurate stepping on plastic film becomes much easier. ## **Surface Treatments for Printing on Plastics** The process to print clear plastic films often requires surface treatments to enhance ink adhesion and quality. Here are the most common methods: ### [Corona Treatment ](https://www.zp-flexopress.com/wp-content/uploads/wp-mfa-exports/post/what-is-corona-pre-treatment.md) - This affordable process uses electrical discharge to polarize the film’s surface, increasing its surface energy and allowing ink to adhere more easily. ### Chemical Treatment - Films are treated with chemicals to change their surface structure, making them more compatible with inks. ### Photochemical Treatment - This method uses UV or laser light to increase the film’s polarity and adhesion, improving how well the ink sticks and performs. ## **Print Sequences for Plastic Film** The order of printing on plastic parts can make a huge difference in your results. Here is how to do it right when you print on plastic film substrates with flexo printing. ### Surface Printing - Apply a layer of white ink first. This bright base makes colors like red, blue, or yellow stand out, just like painting a wall white before adding a bold color. ### Reverse Printing - With this method, you print on the inside of the film, so the image is protected by the film itself. This is ideal for packaging, like snack bags, keeping prints safe from scratches or moisture. | _Tip: Choose the right method for your project—surface printing for bright labels, reverse printing for durable packaging._ | | --- | Product Card – Flexo Label Printing Machine /\* — 产品卡片基础样式 — \*/ .product-card { display: flex; align-items: stretch; border: 1px solid #e0e0e0; border-radius: 8px; padding: 20px; margin: 20px 0; box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08); max-width: 900px; background-color: #ffffff; font-family: ‘Poppins’, sans-serif; } /\* 左侧图片 30% \*/ .product-card .card-image { flex: 0 0 30%; max-width: 30%; margin-right: 25px; display: flex; align-items: center; justify-content: center; } .product-card .card-image img { width: 100%; height: auto; max-height: 200px; display: block; border-radius: 4px; object-fit: contain; } /\* 右侧内容 70% \*/ .product-card .card-content { flex: 1 1 70%; width: 70%; display: flex; flex-direction: column; justify-content: center; } /\* 标题 \*/ .product-card .product-title { margin-top: 0; font-size: 1.4em; color: #222222; line-height: 1.2; margin-bottom: 12px; font-weight: 600; } /\* 参数描述排版 \*/ .product-card .product-description { font-size: 0.92em; color: #444444; margin: 0 0 20px 0; line-height: 1.6; } .product-card .product-description strong { color: #333; font-weight: 600; } /\* 按钮 – 主题色 #0E6EB8 \*/ .product-card .view-product-button { display: inline-block; padding: 10px 28px; background-color: #0E6EB8; color: #ffffff; text-decoration: none; border-radius: 4px; font-size: 1em; font-weight: 500; text-align: center; transition: all 0.3s ease; align-self: flex-start; box-shadow: 0 2px 4px rgba(14, 110, 184, 0.2); } /\* 按钮交互 – 交互色 #f8b62a \*/ .product-card .view-product-button:hover { background-color: #f8b62a; color: #ffffff; transform: translateY(-1px); box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15); } /\* 响应式调整 \*/ @media (max-width: 768px) { .product-card { flex-direction: column; text-align: center; padding: 15px; } .product-card .card-image { width: 100%; max-width: 280px; margin-right: 0; margin-bottom: 15px; margin-left: auto; margin-right: auto; } .product-card .card-content { width: 100%; } .product-card .view-product-button { align-self: center; } } ![](https://www.zp-flexopress.com/wp-content/uploads/2025/11/Satellite-Type-6-Color-Flexographic-Printing-Machine-250m-min-Water-based-Ink-Friction-based-Winding.webp) Satellite Type 6 Color Flexographic Printing Machine for Plastic Films **Colours:** 6 Colors **Max. material width:** 850mm, 1050mm, 1250mm, 1450mm **Max. printing width:** 800mm, 1000mm, 1200mm, 1400mm **Printing length:** 340−1000mm **Printing speed:** 200m/min [ Learn More ](https://www.zp-flexopress.com/wp-content/uploads/wp-mfa-exports/product/satellite-type-6-color-flexographic-printing-machine250m-min-center-driven-winding-auto-loading-and-unloading.md) ## **Conclusion** Successfully printing on plastic needs a deep understanding of different factors. The choice between CI and Stack presses depends on the material thickness and the required registration accuracy. Following this guide ensures that plastic prints are vibrant, clear, and resistant to fading or smudging. RAZP offers the perfect equipment to help you print stand-up pouches, pillow bags, and laminated films like PE and PP. Our [CI flexo machines](https://www.zp-flexopress.com/product-category/printing-machines/flexible-packaging-printing-machines/central-impression-flexo-printing-machines/) and [Stack flexo presses](https://www.zp-flexopress.com/product-category/printing-machines/flexible-packaging-printing-machines/stack-type-flexo-printing-machines/) achieve precise tension control and feature both UV and hot-air drying systems. When you use our machines, you get 10% less film waste, brighter colors, and faster curing for every job. We provide 25 years of experience to help you master printing on plastic sheets with a manufacturing accuracy of ±0.01 mm. 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