An underwrap for a guide is a layer of thread that is wrapped directly onto the rod blank underneath the guide foot before the actual guide wrap is applied. This serves both functional and aesthetic purposes:

• Protection: The underwrap acts as a cushion, providing protection to the rod blank from any direct contact with the guide foot. This is particularly important for heavy-duty rods where high pressure or stress can be applied at the guides, potentially causing damage to the blank.

• Aesthetics: The underwrap adds a decorative element, often in a contrasting or complementary color to the main guide wrap. It can create a visually appealing background that highlights the guide wrap or adds complexity to the rod’s design.

• Durability: For rods used in harsh environments or under heavy loads, the underwrap adds another layer of reinforcement, helping to maintain the rod’s integrity and longevity.

Underwraps are commonly used on larger, heavier rods like saltwater or trolling rods but can be added to any rod for an extra touch of customization and protection.