Each version of the Jr JSA offered subscribers a membership kit. These were posted to the new member in a special envelope with the club logo in the top left corner (Seen on the introduction page of this site). The kits varied through the different ownerships of All-Star Comics from joint DC-AA in 1942, to AA in 1945, then back to DC after the 1948 revival.
Each version of the kit contained a letter of welcome to the new member, a membership certificate, a membership badge or patch, as well as a device to crack the secret Jr JSA coded messages which appears in All-Star and other DC and AA comics. The war-time kits also contained some patriotic material. The following links outline the various sections of the kit in greater detail.
Welcome Letter & Literature
Membership Badges & Patches
& Secret Messages