Stiletto/pointed shapes (D) are the most fragile because most of the nail extends past the support of the nail bed and the narrow point concentrates stress. For a typist or client doing daily manual work, stiletto natural nails will chip, split, or break constantly. Suggest an oval or short squoval instead.

Onycholysis is the painless separation of the nail plate from the bed (without shedding). Causes include trauma, fungal infection, certain medications, or chemicals. Suspicious cases — especially with discoloration — should be referred to a doctor.

Frequent and thorough hand washing is universally recognized as the single most effective infection-control measure. Gloves and disinfectants are supplements, not substitutes.

The hyponychium is the thickened skin underneath the free edge of the nail. It forms a protective seal that blocks bacteria and debris from entering under the nail plate.

Standard 3-stroke technique: load the brush, place it just above the cuticle in the CENTER of the nail (stroke 1), then sweep down each SIDE (strokes 2 and 3). Center first ensures the most polish lands on the visual focal point and the sides blend into it for an even, professional finish.

California licenses cosmetology, barbering, and manicuring through the Board of Barbering and Cosmetology (BBC), part of the California Department of Consumer Affairs.

Onychogryphosis ("ram's horn nail") is severe nail thickening and curvature, most often on the big toe. Causes include long-term neglect, trauma, or poor circulation in elderly clients. Refer to a podiatrist — do NOT attempt to file or cut down in the salon.

MMA causes severe allergic reactions, nail damage, and is extremely difficult to remove. EMA (ethyl methacrylate) is the legal alternative. Use of MMA can cost you your license.

The matrix is the active cell-producing tissue at the base of the nail. Damage here can permanently deform the nail.