Print Like a Pro with Better Trapping and Imposition

High-quality print materials can elevate a brand, create strong impressions, and drive action.

Whether you're designing brochures, booklets, or marketing materials, understanding the basics of trapping and imposition helps ensure your final prints look polished and professional.

Trapping: Preventing Unwanted Gaps in Print

Trapping is a technique that prevents small white gaps from appearing between colors when they don't align perfectly on the press. These gaps can happen due to slight shifts in paper or ink during printing, especially in offset or screen printing.

To avoid this issue, trapping slightly overlaps colors so there are no visible gaps, even if there's a tiny shift. There are two main approaches:

Choke: Slightly reduces the size of a lighter-colored element so it fits better against a darker background.
Spread: Slightly enlarges a darker-colored element to ensure it fully overlaps a lighter background.

Most professional design software, like Adobe InDesign and Illustrator, includes automatic trapping features. However, for complex designs—especially those with thin lines, gradients, or specialty finishes—it's best to consult your printer to ensure optimal settings.

Imposition: Arranging Pages for Efficient Printing

Imposition is the process of arranging multiple pages on a single sheet so that everything lines up correctly when printed, cut, and folded.

Without proper imposition, pages might be out of order or misaligned, leading to costly mistakes in production.

The proper imposition method depends on how the piece will be bound:

Saddle Stitching (stapled booklets): Pages must be set up in multiples of four so they fold and nest correctly.
Perfect Binding (glued book spines): The layout must account for creep, where inner pages shift slightly outward due to paper thickness.
Gang Run Printing (combining multiple designs on one sheet): Helps lower costs but may lead to slight color variations between different designs.

Many design programs can handle imposition automatically, but checking the proof before printing is crucial to avoid surprises.

Ensuring Professional Print Quality

Communicate with Your Printer Early – Ask about their trapping and imposition preferences before finalizing your design. Different printing methods have different needs.
Use Design Software Wisely – Built-in tools help, but for special finishes, spot colors, or unusual layouts, expert input is valuable.
Always Check Proofs – A digital proof is a great first step, but for high-stakes projects, ask for a printed proof to verify color, alignment, and trimming.
Stay Updated on Print Trends – Printing technology is evolving, from eco-friendly inks to specialty coatings. Keeping up with innovations can help make your designs stand out.

Why This Matters

Print is a powerful marketing tool, and attention to detail ensures that your designs look as polished and professional in print as they do on screen.

Understanding trapping and imposition can ensure that colors are crisp, layouts are perfect, and materials look flawless in print. Getting these details right will not only save costs but also ensure that your final printed pieces reflect your brand at the highest level of quality.

Printing Technology

by J. Michael Adams and Penny Ann Dolin

Printing Technology takes readers on a journey from the beginnings of the graphic arts industry through today's cutting-edge digital technology. Now in its fifth edition, this popular book has been reorganized to provide readers with a firmer grasp of how digital printing technologies are revolutionizing the industry. Traditional analog printing methods are reviewed in the first six chapters, establishing the foundation from which readers will develop an understanding of the state-of-the-art technological infrastructure for digital publishing that supports today's new, digital workflow. Subsequent chapters lead readers through the complexities of digital data, digital prepress operations, printing techniques, and finishing options.