Basic Gun Cases and Gun Locks

[God1stGuns2nd]

New gun owner here. Question about transporting guns to the range or anywhere for the matter.

First, background. I have the plastic cases for the guns which have the hole for the gun lock cable that comes with each gun. If I understand correctly, using the gun cable lock through the action is not enough to properly secure the gun while transporting but rather the gun needs to be in a case and the cable lock (or any lock) needs to secure the case from the outside.

Does it matter what the case is made from? The law does not specify a material the case needs to be made from but I assume having the guns in a paper grocery bag wrapped with a cable lock is asking for trouble. I see some fabric gun cases that appear to be secured only by the holes on the zipper heads for a padlock. Is that the way to go if I want cheap bare minimum compliance with the law for the purpose of transportation?

Does the lock need to be special, government approved? Can it be any padlock or cable lock? For argument sake, would a zip tie count as a lock? Or maybe a more ridiculous example, one of those wire ties for a loaf of bread... maybe pass the bread, stuff the guns and tie the bag?