Sport-Tek ST420LS Posi-UV Pro Long Sleeve Tee | UPF 50 Sun Protection Performance Shirt

Sport-Tek ST420LS Posi-UV Pro Long Sleeve Tee — UPF 50 Blank Performance Shirt for Decorators and Bulk Buyers

The Sport-Tek ST420LS Posi-UV Pro Long Sleeve Tee is the go-to blank UPF 50 performance shirt for screen printers, embroidery shops, uniform programs, and bulk buyers who need a high-performance long sleeve that holds decoration and holds up in the field. Built from 4-ounce 100% polyester interlock with PosiCharge color-locking technology, the ST420LS delivers vibrant, print-ready color retention across 15 colorways — from True Navy and True Royal to Bright Seafoam and Soft Coral. Whether you're outfitting a summer sports league, a school spirit program, or a corporate wellness team, the Sport-Tek ST420LS gives you the blank canvas and the technical performance to deliver a finished product your customers will wear again and again.

Decorators who rely on bulk UPF 50 long sleeve performance tees for sublimation and heat transfer programs consistently choose the ST420LS for its tight polyester interlock construction, which accepts ink and transfers cleanly without bleed or distortion. The removable tag means your brand goes on clean — no label interference, no customer complaints. Available in sizes XS through 4XL, this shirt covers every body in your program from youth coaches to adult athletes.

Sport-Tek ST420LS Full Spec Sheet

• Style Number: ST420LS
• Brand: Sport-Tek
• Fabric: 4 oz, 100% polyester interlock
• Sun Protection: UPF 50 rated
• Technology: PosiCharge color-locking
• Moisture Management: Moisture-wicking performance
• Sleeve: Set-in long sleeves
• Tag: Removable for relabeling
• Fit: Unisex performance fit
• Colors Available: 15 — Black, True Navy, True Royal, True Red, Cardinal, Deep Red, Forest Green, Kelly Green, Light Blue, Sapphire, Bright Seafoam, Soft Coral, White, Yellow, Dark Smoke Grey
• Sizes: XS, S, M, L, XL, 2XL, 3XL, 4XL

Fabric and Construction — Why the ST420LS Performs

The 4-ounce 100% polyester interlock construction of the Sport-Tek ST420LS is engineered for active performance environments. Polyester interlock is a double-knit fabric structure that provides more stability and body than single-knit jersey, making it ideal for sublimation, heat transfer vinyl, and screen printing applications where dimensional stability matters. The fabric wicks moisture away from the skin and dries quickly, keeping wearers comfortable during outdoor events, athletic programs, and active workdays.

PosiCharge technology is Sport-Tek's proprietary color-locking system that prevents color fading and dye migration during washing and wear. For decorators, this means your printed or embroidered designs stay sharp and vibrant through repeated laundering — a critical factor for uniform programs and team apparel that gets washed frequently. The UPF 50 sun protection rating blocks 98% of UV rays, making the ST420LS a preferred blank for outdoor programs including summer camps, sports leagues, landscaping crews, and event staff.

Decoration Strategy for the Sport-Tek ST420LS

The ST420LS is one of the most decoration-friendly blank long sleeve performance tees in the Sport-Tek lineup. Its 100% polyester interlock surface accepts a wide range of decoration methods with consistent, professional results.

• Sublimation: Full-coverage sublimation prints bond directly to the polyester fibers, producing vivid all-over graphics with no hand feel. Ideal for custom team jerseys, spirit wear, and branded event shirts.
• Heat Transfer Vinyl (HTV): The tight interlock weave provides a smooth, stable surface for HTV application. Names, numbers, and logos adhere cleanly and hold through repeated washing.
• Screen Printing: Water-based and plastisol inks print cleanly on the ST420LS. The PosiCharge surface requires low-bleed inks for best results — standard practice for any experienced screen printer working on performance polyester.
• Embroidery: The interlock construction provides enough body to support embroidery on chest, sleeve, and back yoke placements without puckering. Use a light cutaway backing for best results.
• DTF (Direct to Film): DTF transfers adhere well to the polyester surface and produce sharp, full-color results with excellent wash durability.

The removable tag is a significant advantage for uniform programs and private-label resale brands. Remove the Sport-Tek tag and apply your own woven label or heat transfer label for a fully branded finished product.

Buying Advantages — Joe's USA Wholesale

Joe's USA ships the Sport-Tek ST420LS from 10 warehouse locations across the country, including facilities in Texas and California, ensuring fast delivery to decorators and buyers in every region. No minimum order quantity means you can order a single shirt or a full team run — whatever your program requires. Wholesale pricing is available on every order, with no account setup or membership required.

• 10 warehouse locations including TX and CA for fast nationwide shipping
• No minimum order — order 1 or 1,000
• Wholesale pricing on every order, no account required
• XS–4XL sizing for full program coverage
• 15 colors in stock for immediate fulfillment
• Fast turnaround for rush decoration and event deadlines

Bulk buyers sourcing blank Sport-Tek performance apparel for wholesale decoration programs will find the ST420LS consistently available across all 15 colors and all 8 sizes, making it a reliable staple for ongoing uniform contracts and seasonal team orders.

Who Buys the Sport-Tek ST420LS

The ST420LS is a versatile blank that serves a wide range of buyer types and program categories:

• Screen Printers and Embroidery Shops: A reliable blank for custom team and event orders. The PosiCharge surface and removable tag make it a professional-grade substrate for any decoration method.
• Schools and Athletic Programs: UPF 50 protection and moisture-wicking performance make the ST420LS ideal for outdoor PE programs, cross-country teams, track and field, and summer sports camps.
• Corporate Wellness and Uniform Programs: Outfitting outdoor staff, facilities teams, or wellness event participants? The ST420LS delivers a polished, branded look with functional sun protection.
• Event Organizers: 5K runs, charity walks, outdoor festivals, and community events rely on performance long sleeves that look great on race day and hold up through the season.
• Resale Brands: The removable tag and clean polyester canvas make the ST420LS a strong foundation for private-label activewear lines targeting outdoor and athletic consumers.
• Bulk Buyers: With no minimums and wholesale pricing, the ST420LS is accessible for small decorators and large distributors alike.

Shop More Sport-Tek Performance Tees and Long Sleeves

• Sport-Tek ST350 PosiCharge Competitor Tee — Lightweight Moisture-Wicking Performance T-Shirt
• Sport-Tek LST420LS Women's Posi-UV Pro Long Sleeve Tee — Wholesale UPF 50 Performance Shirt
• Sport-Tek ST520LS Posi-UV Pro Long Sleeve Polo — UPF 50 Wholesale Performance Polo
• Sport-Tek ST657 Long Sleeve Micropique Sport-Wick Polo — Wholesale Performance Polos
• Sport-Tek ST350 PosiCharge Competitor Tee — Blank Wholesale Performance Tee

Related Sport-Tek Collections

• Sport-Tek Activewear — Wholesale Blank Performance Apparel
• Sport-Tek T-Shirts — Blank Performance Tees for Decorators
• Sport-Tek — Full Brand Collection at Joe's USA