In a grocery store
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You can seal baked goods with a coat of varnish -- including iced baked goods -- as well as vegetables and fruits, as long as they have been fully dehydrated. Varnishing will preserve your food for display and give your items an eye-catching appearance if you use a shiny rather than matte lacquer. Meats and fish will not take well to sealing. The higher fat content of these foods means that they will spoil if they are sealed under a layer of varnish, even if they are fully dehydrated.

Choosing Your Varnish

Purchase clear varnish from a home-supply store or an art store depending on the amount you need. Varnish can be matte or shiny, and the one you use will depend on your personal taste. The varnishes are available either as a liquid that you paint on the food items or in an aerosol can that you spray on. The second is the better option, as you can apply a thinner layer than with brush-on varnish.

Dry It Out First

Before you can varnish your food, dehydrate it so that it will not spoil after it has been sealed. For low-fat baked goods, such as breads, dry the food items slowly in the oven, at the lowest setting. Leave the oven door open so that the food does not burn. For higher-fat baked goods, such as cookies, and items that have icing, such as cakes, set them out to dry at room temperature. Cover the foods with a mesh to prevent insects or rodents from eating them. In cases of fruits and vegetables or prepared dishes like fried rice, use a dehydrator. However, dehydration may change the color of some foods, especially vegetables.

Varnishing Technique

Place your dried food on a sheet of newspaper and then coat the food with a light spray if you are using an aerosol varnish. For a paint-on varnish, brush a thin layer onto the food, keeping the application even and working from a smaller section to a larger one. In both cases, do one side at a time. For example, varnish one side of a slice of bread and allow it to dry thoroughly before varnishing the other side. Do not touch the food while the varnish is drying to avoid leaving fingerprints or debris on the varnish. Apply a second coat of varnish around the entire product after the first layer has fully dried. This increases the durability and longevity of your sealed food.

Arranging Your Food

Decide on the type of effect you would like to create. If you have multiple items to display, such as loaves of bread or several cupcakes, arrange your food in a pyramid shape. Stacking the food items creates height, and placing them next to items that highlight their appearance -- such as against a backdrop in a contrasting color -- gives your display the appearance of abundance. For a minimalist and elegant look, use a cake stand to display a single item or group of items, such as a tiered wedding cake or a multicolored array of cupcakes. In all cases, keep your sealed food out of direct sunlight to reduce the chances of discoloration over time.