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.
One of the first things to consider is what kind of data you have to work with in your cash flow template Excel spreadsheet. Ideally, you're looking for accurate monthly data including income statement items like revenue and operating expenses and balance sheet items like equipment purchases and cash from financing activities. If you have a longer time frame you can go with quarterly periods, but annual tends to be too long. After all, how can you predict what is going to happen beyond 5 years with any accuracy unless you're valuing an annuity?