When it comes to orthopedic bracing and casting, fiberglass cast tape (also called fiberglass casting tape) is a versatile and essential tool. In this blog post, we'll dive into the world of fiberglass cast tape, answering common questions and shedding light on its various uses.
What Is Fiberglass Cast Tape?
Fiberglass cast tape is a strong, lightweight, and durable material used in the medical field to create casts and braces for orthopedic injuries. It consists of a knitted fiberglass fabric impregnated with a water-activated polyurethane resin. Once activated, it hardens to form a sturdy, supportive structure around the injured area.
Compared with traditional plaster, fiberglass cast tape is lighter, more resistant to everyday bumps and moisture, and allows X-rays to pass through more easily. That’s why most modern orthopedic casts are made with fiberglass cast tape instead of plaster alone.

What Is Fiberglass Cast Tape Used For?
Fiberglass cast tape is used for a wide range of orthopedic applications, including:
- Fracture management: It is commonly used to immobilize and support fractured bones, allowing them to heal properly.
- Post-surgery support: After certain orthopedic surgeries, fiberglass cast tape provides stability and protection to the surgical site.
- Sprains and strains: Fiberglass cast tape can be used to treat and support sprains, strains, and soft tissue injuries when rigid support is needed.
Fiberglass Cast Tape Sizes and Typical Uses
Fiberglass cast tape comes in several widths so the cast technician can match the tape to the body part being treated:
- 1.5 inch: Fingers, toes, small pediatric casts, and detailed work around small joints.
- 2 inch: Small wrists, hands, pediatric short arm casts.
- 3 inch: Most standard adult short arm casts, smaller lower-leg casts, and many general applications.
- 4 inch: Long arm casts, short leg casts, and larger adult limbs.
- 5 inch: Long leg casts, thigh and larger limb applications where extra coverage is needed.
If you’re a clinic or patient looking for a specific size or color, you can browse our full selection of fiberglass cast tape here: Fiberglass Casting Tape Collection.
How Does Fiberglass Cast Tape Work?
The working principle of fiberglass cast tape is simple but effective. When the tape is soaked in water, it activates the resin, making it pliable for a short period. This allows the medical professional to mold and shape the tape around the injured area. As it dries, it hardens, creating a rigid and protective cast or brace.
Working Time and Handling Tips for Fiberglass Cast Tape
Most medical-grade fiberglass cast tapes begin to set within just a few minutes after contact with water and reach full hardness shortly afterwards. Because the working time is limited, proper preparation is important. Here are a few handling tips:
- Use cool or room-temperature water to give yourself a little more working time.
- Open only one roll of fiberglass cast tape at a time so it doesn’t start curing prematurely.
- Smooth each layer as you go to improve lamination and create a strong, uniform cast.
- Avoid over-tightening the tape; the cast should be snug but not restrictive.
How to Apply a Fiberglass Orthopedic Cast with Fiberglass Cast Tape
Applying a fiberglass orthopedic cast with fiberglass cast tape should be done by a trained medical professional. The process typically involves the following steps:
- Prepare the materials: Gather all necessary materials, including fiberglass casting tape, stockinette, cast padding, scissors, water, and gloves.
- Protect the skin: Apply a stockinette or padding to the skin to prevent irritation and protect bony areas.
- Activate the tape: Submerge the fiberglass cast tape in water to activate the resin, then gently squeeze out excess water.
- Wrap and mold: Carefully wrap and mold the activated tape around the injured area, overlapping each turn by about half the tape width. Smooth as you go to remove wrinkles and improve strength.
- Check circulation: Ensure that fingers or toes remain warm and pink, and that the patient can move them comfortably.
- Finish the edges: Fold back the stockinette and padding at the edges and cover with an additional layer of tape to create a smooth, comfortable edge.
- Allow to dry: Let the cast dry and harden completely before weight-bearing or strenuous activity, following your clinician’s instructions.
Is Fiberglass Cast Tape Waterproof? Waterproof Casting Options
Fiberglass cast tape itself is water-resistant but not fully waterproof on its own. If standard padding is used underneath, soaking the cast can trap water against the skin and cause skin problems or odor.
To create a true “swim cast” or waterproof cast, a special waterproof liner or stockinette is applied under the fiberglass cast tape. Products like OrthoTape OrthoH2O, Delta Dry, and AquaCast are designed to let water flow through and drain out, so the cast dries more quickly after bathing or swimming.
You can see our waterproof cast options here: Waterproof Cast Kits and Padding.
Fiberglass Cast Tape vs Plaster Cast
Both fiberglass and plaster casts have their place in orthopedics:
- Fiberglass cast tape: Lighter, more durable, more resistant to everyday moisture, and available in many colors. It is often preferred for long-term immobilization and for active patients.
- Plaster cast: Heavier and not water-resistant, but very moldable. It is sometimes used in the initial casting stage, especially when fine adjustments or complex molding are required.
Many clinicians will start with a plaster cast in the acute phase and then switch the patient to a lighter fiberglass cast once swelling goes down.
Where to Buy Fiberglass Cast Tape Online
If you are a clinic, hospital, veterinary practice, or patient looking for medical-grade fiberglass cast tape, OrthoTape offers multiple brands and sizes, including OrthoTape Premium, Techform, and McKesson fiberglass casting tape.
Browse our full selection here: Shop Fiberglass Cast Tape at OrthoTape.
In conclusion, fiberglass cast tape is a valuable tool in the world of orthopedics, offering support and protection for a variety of injuries. When applied correctly and complemented with waterproof options, it can help patients on their journey to recovery.
For high-quality fiberglass cast tape and related products, visit our website, www.Orthotape.com, and explore our extensive range of orthopedic supplies.
Remember, always consult with a medical professional for proper diagnosis and treatment of orthopedic conditions.
Fiberglass Cast Tape FAQ
What is fiberglass cast tape?
Fiberglass cast tape is a knitted fiberglass fabric coated with a water-activated resin. When wet, it can be molded around an injured limb. As it cures, it hardens into a strong, lightweight orthopedic cast.
Is fiberglass cast tape the same as fiberglass casting tape?
Yes. The terms fiberglass cast tape and fiberglass casting tape are used interchangeably. Both refer to the same type of fiberglass tape used to make orthopedic casts and braces.
What sizes does fiberglass cast tape come in?
Fiberglass cast tape commonly comes in widths such as 1.5 inch, 2 inch, 3 inch, 4 inch, and 5 inch. Smaller widths are used for fingers, toes, and pediatric casts, while wider rolls are used for adult arms, legs, and long leg casts.
Is fiberglass cast tape waterproof?
The fiberglass material itself is water-resistant, but the padding underneath is usually not waterproof. To make a true “waterproof” or swim cast, a special waterproof cast liner or stockinette must be used under the fiberglass cast tape.
Can fiberglass cast tape get wet?
Standard fiberglass casts with regular padding should be kept as dry as possible. If a waterproof liner is used, your doctor may allow limited exposure to water, such as showering or swimming, as long as you follow their instructions and let the cast drain and dry properly.
Can patients apply fiberglass cast tape themselves?
No. Fiberglass cast tape should always be applied and removed by a trained medical professional. Incorrect application can cause circulation problems, pressure sores, or poor fracture alignment.
Where can I buy medical-grade fiberglass cast tape?
You can buy medical-grade fiberglass cast tape in multiple sizes and brands directly from OrthoTape. Visit our collection here: Shop Fiberglass Cast Tape at OrthoTape.
