Why it matters
The lock edge is thin. If the core has too little binding strength, the lock can become brittle even when the sample feels hard.
PVC works like the binder
The board construction should be explained clearly enough for the buyer to compare the selected product.
Board construction affects firmness and weight.
PVC gives bonding strength and toughness.
A better balance supports the click-lock profile.
Why the edge detail matters
If the board edge and locking profile are weak, the sample may still look acceptable while the installed floor develops joint problems.
A hard feel is not the same as a reliable locking edge.
A brittle lock can fail before the surface looks old.
The product specification matters more than the SPC name.