Hello, I make jewelry and it has a thin layer of gold plating. As a result, the jewelry discolors back to silver quite quickly. I would like to prevent this with Protecta Clear. Is this skin-friendly and does it keep the color looking good for longer? If so, how long does it stay looking good on average and how many layers do I need to spray? I would prefer to order the spray, but a colleague of yours mentioned that this might cause difficulties with shipping to the Netherlands. Do you also ship to the Netherlands and what are the costs for that? She also suggested that I should order a Preval spray system and Preval power unit; however, I cannot find this anywhere on the website. Where can I find this? And how many ml would you recommend for me to buy? I look forward to hearing from you. Love