Here we have a wonderful 13 inch art glass plate. If you look very closely in the photo you can see a bit of a ring around the inside of the plate.
This is something that seems would wash off, but I think it would need a little polishing. The line is very superficial.
Made in Sweden by the late Ulrica Heidman Vallien. The item "Kosta Boda Hand Painted Ulrica Hydman Vallien Signed Heart 13 Art Glass Plate" is in sale since Saturday, January 25, 2020. This item is in the category "Pottery & Glass\Glass\Art Glass\Scandinavian\Kosta Boda". The seller is "aloha_classics" and is located in Eugene, Oregon. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Costa rica, Dominican republic, Panama, Trinidad and tobago, Guatemala, El salvador, Honduras, Jamaica, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Turks and caicos islands, Bangladesh, Brunei darussalam, Bolivia, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Luxembourg, Monaco, Macao, Martinique, Nicaragua, Pakistan, Paraguay, Uruguay, Russian federation, South africa, Colombia, Antigua and barbuda, Saint lucia, Barbados, Bermuda, Cayman islands, Sri lanka, Maldives, Oman, Reunion, Montserrat.