What type of cups keep water cold?

Insulated cups are the best at keeping water cold. They have a double-walled design with a layer of insulation in between, which helps to prevent heat from transferring from the outside of the cup to the water inside. Some insulated cups also have a copper lining, which is a very effective conductor of heat and helps to keep the water even colder.

Here are some of the most popular types of insulated cups:

* Stainless steel cups. These are the most durable type of insulated cup and are available in a variety of colors and styles.

* Plastic cups. These are lighter and less expensive than stainless steel cups, but they are not as durable.

* Ceramic cups. These are a good option for keeping water cold at home or in the office.

* Glass cups. These are the least effective at keeping water cold, but they are a stylish option for entertaining guests.

No matter what type of insulated cup you choose, make sure it has a tight-fitting lid to help keep the water cold. You can also add ice cubes to your water to help keep it even colder.