When you need durability _ Key card envelopes can be made in Tyvek as well as paper. Tyvek is tear_proof and water_resistant, and is an excellent choice when you need the envelope to be durable. If the card is something a person will hold onto for a long time, Tyvek is a better choice than paper. Key cards may only be used for a few days, but ID cards, ATM cards, and other cards that are distributed in envelopes might do better in Tyvek. A more durable envelope means the instructions for use will not fade or be lost when a paper envelope tears.
Finally, when applying discount factors, where do you intend to get your discount numbers? For a company with existing debt and equity capital you can calculate WACC and use that. For a startup company you need to figure out a risk_adjusted cost of capital that makes sense. Usually this is not just a risk_free rate which only the largest companies in the world have access to. It's probably something higher.