A handy package is the Druggist Fold. It was a method used by pharmacy clerks to package medicines. Police officers use the method because they always have paper on hand. It is done as follows:
Lay a piece of paper lengthwise in front of you.
Fold it in thirds.
Turn it so the length is up and down.
Fold it in thirds again.
Tuck the ends in so that one full end is enclosed in the other end.
If you did it right, nothing can slip out accidentally.
Never ever use plastic. It traps heat and moisture.
Paper bags are used for clothing, fibers, larger objects that are light weight.
Metal cans are used for burned debris and larger amounts of body fluids.
Glass vials are used for blood and smaller amounts of body fluids.
Clear, breathable polymer envelopes are used for paper documents.
Boxes are used for guns and heavier evidence.