Screen Printing Underbase: Why & When to Print White First

If you've been screen printing for more than a few months, you've probably heard the term underbase—and maybe wondered if it's a necessity or just extra work. The truth? It depends on your design, your garment, and your profit margins.

An underbase is a layer of white (or sometimes light-colored) ink printed first, before your design colors go down. It acts as a foundation that makes subsequent inks appear more vibrant, opaque, and true-to-color—especially on dark fabrics. But it also adds time, cost, and complexity.

This guide walks you through exactly when to recommend an underbase, how to charge for it, and how to decide if it's right for your shop.

What's an Underbase & How Does It Work?

When you print a design directly onto a dark garment—say, navy blue—your inks sit on top of the fabric. The dark color beneath can dull or shift the appearance of your design colors. This is especially noticeable with bright colors like red, yellow, or light pink.

An underbase solves this by creating an opaque white (or light) layer first. Your design colors then print over that white layer, where they appear exactly as mixed—vibrant and consistent, regardless of the garment color underneath.

Think of it like painting a white primer on a dark wall before applying your final paint color. The primer ensures the final color looks true.

When Underbases Matter Most

• Dark garments (navy, black, heather, dark gray)
• Bright, light design colors (neon yellow, bright red, light pink, white)
• High-quality/premium orders where color accuracy is critical
• Photographic or gradient designs where color shift is visible
• Specialty inks like discharge or low-cure inks where opacity matters

When You Probably Don't Need One

• Light or medium garments (white, ash, light gray)
• Dark ink colors on dark garments (black ink on navy)
• Simple, solid designs where slight color shift is acceptable
• Budget orders where cost is the primary driver

The Cost & Time Impact

An underbase isn't free. You need to account for:

• Extra press time: One additional print cycle (typically 20–40 seconds per garment depending on your press and flash cure setup)
• Extra white ink: Usually 5–10% more ink per shirt
• Screen cost: A dedicated underbase screen if you're running multiple designs (though you can often combine it with a single-color flood or use a separable screen)
• Labor: Slightly longer per-piece time and additional quality checks

Real numbers: An underbase typically adds $0.30–$0.75 to your cost per garment, depending on garment size, ink viscosity, and whether you're using a separate screen or combining it with existing screens.

Many shops charge $1.50–$3.00 extra for an underbase to account for the material cost plus the labor and complexity. The markup ensures you're not absorbing the cost of better color accuracy.

Technical Considerations: Coverage & Registration

Not all underbases are created equal. Here's what separates a good one from a problematic one:

Coverage

Your underbase needs to be opaque and even. If it's too thin, dark fabric will bleed through. If it's uneven, your design colors won't sit consistently on top.

• Use white ink with good opacity (not all white inks are equal—some are more translucent)
• Print at appropriate squeegee pressure and flood stroke consistency
• Consider your mesh count—a 110 or 156 mesh is typical for underbases (higher mesh = thinner coverage)

Registration

Your design colors must align precisely with the underbase. Any misalignment means color showing through in the wrong places.

• Use index marks on your screens (or ask your screen printer to add them)
• Verify your press registration before running production
• On manual and semi-automatic presses, check every 10–15 shirts; on automatics, use built-in registration systems

When Should You Recommend an Underbase?

As a shop owner, you want to proactively offer underbases—but not push them where they're not needed. Here's a decision framework:

Always offer if:

• The design is bright or pastel colors on dark garments
• The customer specifically asks for "vibrant colors" or mentions the garment is dark
• It's a quality-sensitive order (promotional gifts, corporate wear, high-value orders)

Mention as an option if:

• The customer provides a dark garment and hasn't specified color requirements
• The design has gradients or photographs that need color accuracy

Skip if:

• Customer explicitly says budget is the priority
• It's light ink on a light garment
• The design is primarily dark colors (which don't need white underneath)

Many successful shops use their order management system (like Kontraktr) to flag designs that might benefit from an underbase, so you can make a smart recommendation before production starts.

Balancing Quality & Profit

The real question: Is an underbase worth it for your bottom line?

Consider this:

• If you charge extra: You're adding $1.50–$3.00 revenue per shirt with minimal additional material cost—good margin
• If you include it free: You're absorbing the cost, which erodes profit on lower-margin orders
• If you skip it on orders that need it: Customers might reject the work or leave bad reviews, costing you far more than the underbase would have

Best practice: Offer underbases as an optional upsell and educate customers on the quality difference. Most will choose quality if they understand the cost is reasonable.

For dark garments with bright designs, stop treating it as optional—build it into your default process and price accordingly. Your rejects and customer satisfaction will both improve.

Quick Action Items

1. Review your last 10 dark-garment orders. How many had bright colors? How many might have benefited from an underbase?
2. Calculate your true underbase cost (ink + screen + time) and set your pricing to cover it plus margin.
3. Create a simple customer-facing note on your quote templates explaining when underbases improve color, so customers aren't surprised by the upsell.
4. Test your underbase process on a small batch to dial in screen specifications, ink coverage, and registration—don't wing it on a 100-piece order.

Done right, underbases aren't a cost burden—they're a quality tool that builds customer satisfaction and protects your reputation on the jobs that matter most.