Some secret product that only professional sewers use. It is sewn into many garments, but the general public is unaware of it's existance.
While at the fabric store, you will see many buy it, but no one will tell you it's use.
May be some secret substance holding the world together.
Comes in two forms. Regular and iron on.
Grandma to grandchild " Now honey, you go fetch grandma some of that pellon over there, never you mind what it is for. "
As I was going through the sewing box, the pellon was quickly ripped from my hand by my frantic mother.
At this time it is believed that only members of the secret sewing guild are known to hold the secret.
Wow, that pavement sure cracked up quick, they must not have put enough pellon in the mix.