Procedure to send docs to Mumbai consulate

[want2go2us]

Hello All,
Earlier I remember there was some guidelines/stipulations for sending documents prior to attending the interview to VFS for Mumbai consulate. e.g. the documents need to be sent in a cloth linen envelope etc. Now are there any such stipulations or we can send it in any type of enevelope etc. Any information or official link would be appriciated.
Thanks in advance

[immihelp]

Read https://www.immihelp.com/us-visa-application-procedure/

There is no rule about the type of envelope to be used.