The Purpose of Coating in Screen Printing

Stencil Creation

The coating becomes the stencil once exposed and washed out, defining where ink is deposited on the garment.

Ink Control

Proper coating thickness helps regulate ink flow, ensuring consistent coverage and clean edges.

Print Durability

A well-coated screen withstands long print runs without stencil breakdown.

Types of Coatings Used in Apparel Printing

Photopolymer Emulsions

These single-component emulsions are easy to use and ideal for plastisol ink printing.

Dual-Cure Emulsions

Combining photopolymer and diazo elements, dual-cure coatings offer greater durability and flexibility.

Water-Resistant Emulsions

Designed for water-based and discharge inks, these coatings resist moisture during printing.

How Coating Is Applied to Screens

Scoop Coater Application

A scoop coater is used to apply an even layer of emulsion to both sides of the mesh.

Mesh Count Considerations

Lower mesh counts require thicker coatings, while higher mesh counts need thinner, controlled layers.

Drying Conditions

Coated screens must dry in a dark, dust-free environment to prevent defects.

Coating Thickness and Print Results

Thin Coatings

Produce sharper detail and are ideal for fine lines and halftones.

Thick Coatings

Allow heavier ink deposits, suitable for bold designs and specialty inks.

Balanced Coating

Achieving the right balance is essential for professional-quality prints.

Common Coating Issues and Solutions

Uneven Coating

Caused by poor technique or damaged scoop coaters, leading to inconsistent prints.

Fish Eyes and Pinholes

Dust, oil, or moisture contamination can create small defects in the coating.

Under- or Over-Exposure

Incorrect exposure times can weaken the coating or make washout difficult.

Practical Considerations for Australian Print Shops

Climate Control

Humidity and temperature variations, especially in Australian summers, can affect coating performance.

Screen Storage

Proper storage prevents premature exposure and coating damage.

Training and Technique

Consistent coating requires practice and attention to detail.

Coating and Ink Compatibility

Plastisol Inks

Most standard emulsions work well with plastisol inks.

Water-Based and Discharge Inks

Require water-resistant coatings to prevent stencil breakdown.

Specialty Inks

High-density or abrasive inks may require more durable coatings.

The Role of Coating in Professional Apparel Printing

Coating is a foundational step in the screen printing process that directly impacts print quality and efficiency. By selecting the right coating type and applying it correctly, Australian garment printers can achieve consistent, durable, and high-quality prints across a wide range of custom apparel applications.