1. When it is slightly soiled, first pour the neutral detergent into warm water at about 3 degrees Celsius, and then put it into clothes and gently pat it with your hands.
2. Wash it in warm water at about 4 degrees Celsius for several times until it is clean;
3. Add a little vinegar or softener to clean water, and put the washed leather-lined collar into a cloth bag and dehydrate it in the washing machine for 1 to 2 minutes;
4. Smooth the leather lined collar and iron it with a steam iron at 12℃ to 14℃. The iron should not directly touch the leather lined collar;
5. The leather lined collar can be flattened and dried after shaping.