Baseball Under-Glove Guide

An under-glove is a layer, not a glove in its own right. It is thin enough to disappear inside a fielding glove, cut to fit the hand closely, and made of a fabric that grips the leather lining on one side and the skin on the other. Players have worn thin gloves under fielding gloves for a long time, usually batting gloves; a purpose-made under-glove is thinner and does not carry a batting glove's padding or strap.

The Bass Second Skin is recorded as "ultra-thin, form-fitting" with "a zero-bulk, natural bare-hand feel", and it is made to be worn beneath a fielding glove. Its record also notes it can be worn inside a batting glove.

The under-glove goes on first, pulled so the seams sit between the fingers and the palm lies flat. The fielding glove goes on over it. Because the layer is thin, the fielding glove should fit exactly as it did without one: the hand seated to the back of the pocket, the fingers in their stalls, the wrist closure at the same setting. An under-glove is not a way to make a glove that is too big fit; it is a way to make a glove that fits stay put.

The Second Skin's wristband is recorded as low-profile and elastic, so it sits under the fielding glove's wrist opening rather than fighting it.

The grip is on the outside of the under-glove, facing the glove's lining. The Second Skin's record describes "an advanced hexagonal palm and finger grip pattern" that "prevents hand slippage inside your primary glove", so the hand and the glove move as one on the catch and the transfer. That is the whole reason to wear one: a glove that does not rotate on the hand puts the pocket where the fielder aimed it.

A layer that grips the glove must still let the hand close. That is the argument for thinness: the Second Skin is recorded as zero-bulk with a natural bare-hand feel, so the fingers close the glove as they would bare. A thicker glove worn as an under-glove adds material at the knuckles and the finger joints, which is the part of the hand that has to bend.

Sweat is the other reason players wear one. A bare hand in a leather glove on a hot day slides, and the leather takes the sweat. The Second Skin's record describes a moisture-wicking material that "keeps hands dry, cool, and comfortable under high-intensity game conditions". Some players also simply prefer fabric against the skin to a glove's lining.

An under-glove is sized to the hand, and it should be close-fitting: a loose under-glove wrinkles inside the glove, which is worse than no under-glove at all. The Second Skin is listed in adult M, L and XL. A player's batting glove size is the natural starting point, and between two sizes the smaller one is the closer fit.

It is sold for one hand at a time: the glove hand. A right-handed thrower wears a fielding glove on the left hand and buys the left-hand under-glove; a left-handed thrower buys the right. The fielding glove sizing guide explains the RHT and LHT convention.

• A glove that fits but still turns on the hand on hard contact.
• Hands that sweat, and a glove lining that has become slick.
• Hot weather and long days: tournaments, doubleheaders, summer ball.
• A player who dislikes the feel of a leather lining on bare skin.
• A player who has been wearing a batting glove under the fielding glove and wants the same security with less bulk.

Not every fielder needs one. A glove that fits well and a hand that does not slide are the goal; the under-glove is one way to get there, and a player who already has both can leave it on the shelf.