Coils were made from ordinary post office sheets. A special coil plate was not produced. Similar to other coil issues, coil sheets were freely available and are normally collected as blocks of four. Note however that Helecon coils were not sold as sheets and are collected as traditional pairs.
with thanks to JOHN ACKERMAN
The final coil rolls were made up from mixtures of helecon and non helecon sheets.
For this reason, it is possible to collect coil joins with one stamp heleconised, the other, not. The incidence is rare because it only occurred during the next ream of printed sheets (normally a gross of 144) being used in the middle of creating the rolls of 720 stamps.
coil plate #3