These briefs are ready to wear right out of the package. For optimal fit, select your standard UK dress size. They are designed to be compatible with a wide range of outerwear due to their invisible fit, and specifically with matching Triumph Amourette bras for a coordinated lingerie set. To maintain the quality and longevity of your Triumph Amourette 300 Maxi Briefs, they are machine washable. Always refer to the care label inside the garment for specific temperature settings and washing instructions to preserve the delicate lace and fabric integrity. Generally, a gentle cycle with similar colors is recommended, and air drying is preferred over tumble drying to protect the elastic and lace.