GRG vs Acrylic Panels? Differences in Light Transmission and Durability?

A Core Dimension Comparison of GRG vs Acrylic Panels: A Selection Guide from Light Transmission to Durability

In the material selection stage for indoor shaped decoration and commercial space styling projects, GRG and acrylic panels are two popular options often compared. Many project owners struggle with the differences in light transmission performance, long-term durability, and suitability for different scenarios. As a professional service provider with nearly 30 years of dedication to the R&D and production of new decorative building materials, we draw on measured data from over a thousand completed projects to objectively break down the core characteristics of both materials, helping you clarify the key criteria for selection.

1. Measured Light Transmission Comparison: The Two Materials Work on Completely Different Principles

When first encountering the two materials, many people mistakenly assume that both can achieve light transmission, but their actual performance differs significantly. First, regarding the light transmission of GRG—that is, glass fibre reinforced gypsum—standard GRG itself does not have light-transmitting properties. Only by adding light-transmitting aggregates and adjusting the mix density of the gypsum matrix during production can a semi-uniform, diffused light transmission effect be achieved. Light passing through presents a soft textural quality without obvious light spots, making it suitable for scenarios such as theatre ceilings and exhibition background walls that require concealed ambient lighting and pursue an overall even light and shadow. The uniformity of the light-transmitting layer can be controlled through production processes, with no local variations in brightness. Acrylic panel transmission, by contrast, is of the highly transparent, direct type: light passes through with almost no diffusion, clarity is high, and transmittance can reach over 90%, making it better suited for high-transparency displays, signage light boxes, and similar applications. However, for curved shapes, the transmission uniformity of heat-bent acrylic is prone to deviation, and areas with uneven thickness will show obvious shadows.

According to test data from actual projects, custom light-transmitting GRG of the same thickness offers an adjustable transmittance range of 30%-60%, while standard clear acrylic stays fairly stable at 85%-92%. Their application scenarios do not overlap at all: if the project calls for a soft light-and-shadow effect on an overall seamless curved surface, GRG is the better fit; for high-transparency, lightweight flat display scenarios, acrylic's cost advantage is more prominent.

2. Durability Differences: A Comparison of Key Pain Points in Long-Term Use

Durability is the most easily overlooked core difference between the two materials, and also the main reason many projects run into maintenance issues later on. First, weather resistance and deformation resistance: GRG's matrix is inorganic gypsum, inherently non-combustible, with a fire rating of up to Class A. It does not thermally deform in indoor ambient environments and does not yellow or age under normal use. In several of our indoor GRG projects that have been in service for over 10 years, the surfaces show no obvious discolouration or cracking. Acrylic, on the other hand, is an organic polymer material with a fire rating of only Class B. Under prolonged exposure to direct lighting or high temperatures, it is prone to yellowing and thermal expansion deformation—especially large-size acrylic thicker than 5mm, whose deformation rate rises noticeably in high summer temperatures.

Next, durability after shaping: GRG can be integrally moulded into large-size double-curved and irregular curved surfaces, with a single panel reaching 3 metres or more. After joining, seamless treatment can be achieved, and long-term use will not cause joint cracking due to deformation, offering stronger structural stability. Acrylic, to form irregular curves, must undergo heat bending, which changes the molecular structure at the bent areas, making stress cracks likely at load-bearing points. The later damage rate of large heat-bent acrylic is far higher than that of integrally moulded GRG. Additionally, in terms of environmental performance, GRG does not release volatile organic compounds during production and use, whereas acrylic emits a slight organic odour in high-temperature environments—worth extra attention in enclosed indoor settings.

3. Selection Recommendations for Different Scenarios

Based on the characteristics of the two materials, you can make the selection decision directly according to the project's actual needs: for indoor curved ceilings and background wall decoration in theatres, exhibition centres, and high-end commercial spaces that require concealed ambient lighting and pursue a seamless overall look, GRG is the preferred choice—it has lower long-term maintenance costs and more stable presentation results. For flat light boxes, small display signage, and scenarios that do not require complex curves, acrylic offers lower procurement and processing costs and shorter delivery times.

At present, many peers in the industry also combine the two materials, applying an acrylic light-transmitting layer over the GRG substrate to balance curved surface stability with high light transmission needs. You can also make customised process adjustments according to your project's specific requirements.

Frequently Asked Questions

Q1: Can light-transmitting GRG achieve the same high transparency as acrylic? A: Standard custom light-transmitting GRG has a maximum transmittance of around 60% and cannot match acrylic's high transparency of over 90%. The two work on different transmission principles and are not interchangeable.

Q2: Can acrylic be used in large indoor curved decoration projects? A: Small-size curved acrylic can be used, but large sizes have a higher long-term deformation rate and a greater risk of damage during later maintenance, so integrally moulded GRG is more recommended as a substitute.

Q3: Is GRG's later maintenance cost high? A: GRG is an inorganic material and requires basically no additional maintenance in normal indoor use. Surface stains can simply be wiped off with a neutral detergent, and its service life can exceed 15 years.