Copper is a soft metal and is susceptible to dings. Copper sheeting is sold by ounces per square foot. For a countertop, look for a sheet of copper that is at least 16 oz. per square foot. Copper sheets that weigh 20 oz. per square foot would provide added strength to prevent dents.
Copper sheets are malleable and easy to form. Installation must be on a flat, solid substrate. The sheeting is typically attached with adhesives. In some cases copper, brass or bronze fasteners are used. Seams and corners are usually soldered and polished to match the copper surface.
Copper sheets come in various sizes. Since most counters are 24 inches deep a sheet 36 inches wide would be easiest to work with for a home improvement project. Sheets typically come in 48-inch lengths requiring seams. Consider where seams will go and try to minimize them in high use areas of the counter.
Those who prefer to keep copper shiny will seal the surface with a food grade sealer and buff and polish the surface frequently with applications of beeswax. Care will need to be taken to minimize scratches, dents and stains.
Most people choose copper sheet countertops for the patina that develops as it ages. Unfinished copper is naturally antimicrobial requiring simple soap and water to clean. An occasional application of beeswax will remove fingerprints. This maintenance method allows scratches, dings and stains to all add to the patina of the countertop over the years.