Fill a sink full of lukewarm water. Use a full sink of water even if only one or two antique handkerchiefs are washed.
Add 2 tablespoons of mild, non-bleach, liquid laundry detergent to each gallon of water. Mix the detergent thoroughly into the water by hand.
Soak the antique handkerchiefs in the soapy water for approximately 30 minutes.
Massage the fabric gently, using both hands. Do not rub the fabric against itself or another handkerchief to avoid damaging the material.
Empty the soapy water from the sink and clean it of soap residue.
Rinse the handkerchiefs thoroughly under low-pressure, lukewarm, running water.
Fill the sink with clear lukewarm water and soak the antique handkerchiefs for approximately 30 minutes. Massage the handkerchiefs gently to work out soap residue that damages the fabric during storage.
Rinse the handkerchiefs under low-pressure, lukewarm, running water.
Lay the handkerchiefs out flat on top of a clean, dry white towel. Place another towel on top of the antique handkerchiefs and press lightly to extract most of the water.
Hang the antique handkerchiefs on a clothesline with one clothespin securing it on each side. Hang the handkerchiefs in the shade if possible, and do not leave it longer than necessary after it is dry.