To get the best care for your gown we recommend you use a specialist gown cleaning and preservation service. Always check that the company does the cleaning themselves as a lot of companies use wholesale dry cleaning services and your gown could be cleaned with 20 - 30 others and anything that is on them could end up on yours.
Try to find a cleaner that cleans gowns one at a time and cares about its equipment and the quality of its staff. The company should comply with BS1 TC1/82 standards and meet the compliance requirements.
Always store your dress in a breathable gown cover. Check regularly and keep away from any conditions that could be detrimental to your gown, such as excessive light, heat, smells, damp etc.