The wall and ceiling surfaces inside a grow room do more than hold things together. They reflect light back onto your canopy, resist moisture and mold, and determine how cleanly you can wipe down and sanitize the space between cycles. Choosing the wrong material costs you in reflectivity, durability, or both — and retrofitting a built-out room is far more expensive than choosing correctly the first time.


This guide covers the four materials most commonly used in grow rooms: FRP panels, white PVC panels, panda film, and mylar. Each has a legitimate use case. Here's how they compare.


The Key Property: Diffuse White vs. Specular Mirror

Before comparing materials, it's worth understanding why diffuse white reflection outperforms mirror-like surfaces in grow rooms.


A specular (mirror) surface reflects light at a single angle — angle in equals angle out. This creates hot spots under your lights and uneven coverage at canopy edges. Plants directly under the light get hammered; plants at the margins get less.


A diffuse white surface scatters light in all directions simultaneously. Every point on the wall reflects light toward every point in the room, distributing photons evenly across the canopy. This is why every commercial grow facility uses white walls, not mirrors — and why high-quality FRP and PVC panels outperform mylar in real-world applications despite mylar's higher theoretical reflectivity.


FRP Panels (Fiberglass Reinforced Plastic)

FRP is the clear first choice for a purpose-built grow room. It's the same material used in commercial food processing facilities and restaurant kitchens — bright white, moisture-proof, mold-resistant, and built to handle decades of wet conditions.


Reflectivity: 85–90% (diffuse white)

Format: Standard 4×8 sheets, smooth or embossed texture

Cost: $40–$75/sheet retail; $640–$1,350 for a 10×10 room (16–18 sheets)

Installation: Screws, panel adhesive, or both. FRP moldings cover seams.

Lifespan: 20+ years with normal use


The standout product is Crane Composites Glasbord — a grow-room-specific FRP line with a SURFASEAL antimicrobial coating that resists moisture penetration and bacterial growth. It's what serious permanent installations use.


FRP is the most labor-intensive of the four options to install, but it's the only material that truly belongs in a permanent grow room. Once installed, it's done — no re-hanging, no tears, no replacement.


White PVC Panels (Trusscore, Duramax)

White PVC wall planks are a strong alternative to FRP, particularly for growers who want a clean look with slightly easier installation. Brands like Trusscore and Duramax produce interlocking plank systems that snap together without adhesive.


Reflectivity: 88–92% (diffuse white)

Format: Interlocking planks, various widths

Cost: Comparable to FRP; Trusscore runs $3–$5/sq ft

Installation: Snap-together system, faster than FRP sheet installation

Lifespan: 15–20 years


Trusscore in particular markets to grow room applications and claims 90% light reflectance. The plank system is forgiving of imperfect walls and easier to cut to size than 4×8 sheets. For growers who want high performance without dealing with FRP adhesive and molding installation, PVC planks are a legitimate alternative.


Panda Film

Panda film is a black-and-white polyethylene sheet — white on one side, black on the other. The white side provides a reasonable reflective surface; the black side provides complete light blockage. It's inexpensive, lightweight, and easy to hang.


Reflectivity: 85–90% (diffuse white side)

Format: Rolls (typically 10ft wide × various lengths)

Cost: $0.15–$0.30/sq ft — extremely cheap

Installation: Tape or staple to framing. No adhesive needed.

Lifespan: 2–5 years before degradation, tearing, or replacement


Panda film is the right call for temporary setups, grow tents, or anyone building a first grow room on a tight budget. The reflective performance is comparable to FRP. The downside is durability — it tears, accumulates pathogens in surface creases, and needs periodic replacement. It's also harder to clean thoroughly than hard panels.


For a permanent installation, panda film is a compromise. For a temporary one, it's perfectly adequate.


Mylar

Mylar is a metalized polyester film — the silver mirror-like material you've probably seen in grow tents. It has the highest theoretical reflectivity of any material on this list, but in practice it underperforms FRP and white PVC for the reasons explained above.


Reflectivity: 92–97% (specular mirror — creates hot spots)

Format: Rolls

Cost: $0.10–$0.25/sq ft

Installation: Tape or staple. Must be kept smooth — wrinkles scatter light unpredictably.

Lifespan: 1–3 years; tears, wrinkles, and degrades quickly


The real-world problem with mylar: it's nearly impossible to keep smooth. Every wrinkle creates an unpredictable reflection angle. It tears easily, doesn't clean well, and the metalized surface can harbor pathogens in microscratches. The specular reflection means it's actively worse than white diffuse surfaces for even light distribution.


Mylar's only remaining use case is lining the inside of tents where it's pre-installed at the factory and kept under tension. For wall application in a built room, it's outclassed by every other option on this list.


Head-to-Head Comparison

FRP Panels: Best overall for permanent rooms. Highest durability, cleanest surface, moisture-proof, easy to sanitize. Higher upfront cost pays off over years of use.


White PVC Planks: Close second. Slightly easier to install than FRP, comparable reflectivity and moisture resistance. Strong choice for permanent installations.


Panda Film: Best for temporary or budget builds. Excellent reflectivity, minimal cost. Not suited for permanent installations where sanitation and durability matter.


Mylar: Avoid for wall application. High theoretical reflectivity, poor real-world performance due to specular reflection and wrinkling. Better materials are available at similar or lower cost.


What Verdure Recommends

For a permanent grow room: FRP smooth white panels, specifically Crane Composites Glasbord with SURFASEAL coating. Budget for 16–18 sheets for a 10×10 room at current pricing. Pair with FRP inside corner molding and H-molding for a clean, professional finish.


For a budget or temporary build: Panda film. Cheap, effective, and replaceable. Accepts that you'll redo the walls when you build permanently.


Skip mylar for wall applications entirely.


No hydroponic retailer currently sells FRP panels — this is a category Verdure is actively working to stock. In the meantime, Crane Composites products are available through ABC Supply Interiors and regional building supply distributors.