Lay out enough plastic wrap to cover the salmon. Place half the salt mixture on the wrap. Place the salmon on top of the mixture and coat with the remaining salt mix. Wrap the salmon tightly, make sure the salmon is completely coated. Place the salmon in a container to catch any liquid that might escape. Weigh down the salmon and refrigerate for 12 hours and up to 2 days. Salmon should be firm but not hard. Rinse the salmon and pat dry. Slice thinly to serve. Store refrigerated in an airtight container.