These are optional. Please bear in mind that these items may be available through other sources at better prices, but many people like the one stop shop approach of an office supply store. Blank CD-R's can be bought in bulk, often in spindles of 50 or 100 for far less than you'll pay for branded TDKs at an Office Max. However, you need to remember that the discs you buy need to work in other people's burners. Also, if you can find a smaller envelope than the 9x12 Tyvek for shipping there, that the bubble mailer will fit into, use it.
Some traders have a hard time getting the large envelope delivered to their residence.
And many people find that manila envelopes will work just fine, but some prefer the strength of the Tyvek envelopes. Try to avoid buying the mailers that are padded with paper fiber. Some traders feel that these kind of mailers can contaminate the CD-R's with small particles, especially since the packages seem to easily get statically charged and can rip when opening. Jewel Cases will usually not survive the shipping, and add significantly to the postage costs. So take the required number of discs and place them into either clamshells or Tyvek sleeves.