Which of the following is NOT a concern when applying dope?

When applying dope, the color of the fabric is not a primary concern compared to other factors. The primary function of dope is to provide protection to the fabric, enhance its durability, and improve its adherence to the aircraft structure. While the color of the fabric can affect its appearance and possibly its thermal properties, it does not impact the application of the dope itself or the performance of the covering.

On the other hand, drying time is crucial because it can affect how multiple coats are applied and the overall finishing of the fabric. Material compatibility is essential as different fabrics and dopes need to work well together to avoid issues like chemical reactions or adhesion problems. Application technique also plays a significant role in achieving a smooth and effective coating, ensuring that the dope is evenly distributed and adequately covers the fabric. Thus, fabric color stands apart as it does not directly influence the application process or performance of the covering like the other concerns do.