Eucaboard panel

​I have not personally used this type of hardboard. I have sent your question to a few other moderators.

​Hi. Sorry for the later response but I only just now received the following response from Elaine Salazar at Ampersand Art Supply
We did a bit of research on the Eucaboard mentioned in the Mitra comments and wanted to provide some information that may be helpful to your readers. First remember that the key for using any wood substrate for artwork is to a) determine its dimensional stability and stiffness as you want your work to remain flat and to weather the transition through different ambient climates, and b) to use the proper methods for sealing and finishing the wood substate to protect your artwork over time. One of the most important characteristics of the mentioned Eucaboard is that it is an S1S (smooth one side), which means that only one side is tempered and smooth and the back side has a screen back. This perhaps is the major reason that we would not recommend use of this surface for a painting. These screen back boards are highly susceptible to moisture penetration as the screen backs have exposed fibers that can accept a lot of moisture, leading to excessive warping. It is also difficult to “seal off” these screen backed boards whether Eucaboard or any other type of hardboard. The difference between the smooth surface on one side and the screen-back surface on the other is that it creates an unbalanced substrate. When applying the sealing gesso or polymer to prepare the surface for painting, these boards tend to warp more than an S2S (smooth two sides) panel. We also found that based on the technical specifications provided by the manufacturer, the dimensional stability of these panels has a much lower rating than other options available in the marketplace. We always recommend that artists look carefully at the technical data sheets and specifically look at the densities of the substrates that are being used for painting. Density translates into moisture and warp resistance when working with wood substrates. The lower density boards like MDF as compared to HDF (high density fiberboard) experience much more warping and movement. While Eucaboard is listed as a high-density fiberboard, upon further review of their technical sheets we found that the density (as measured by lbs./sf) is closer to 49 lbs./sf as compared to an S2S (smooth two sides) tempered hardboard which is typically 65 lbs. /sf. Also, Modulus of Rupture (MOR) is important because it measures the strength of the substrate. This characteristic is measured by psi (pounds per square inch). The Eucaboard has an MOR of 4480 psi as compared to an S2S hardboard that has a 6500-7000 psi MOR.   Finally, just a note about the Eucaboard and its wood source. Eucaboard is produced in Brazil by Eucatex. The wood pulp for the Eucaboard comes from fast growing Eucaplytus trees. There is some controversy on the environmental impact of this ‘cash crop’ around the world and its impact on forests.”