How much wax to seal bathed bottles

I'm searching for a guide to how much/thick to make the wax seal on water bath processed bottles of jam? I don't think my childhood memories are a reliable guide...
is it a thickness? percentage? ratio opening diameter:container depth?

Steven, this is a no longer recommended method. Over time, paraffin wax shrinks and expands with temperature changes leaving the jam and jelly susceptible to growth of molds and yeasts

For a better explanation:
   
https://pickyourown.org/jamsjelliesparaffinwaterbath.php

I wonder what the wax is that they use to cover cheeses? It's slightly formable when cold, presumably safe in contact with food, so might be a better option than paraffin wax.

source

A bit of web surfing and I find out about microcrystalline wax which is refined from paraffin wax to give specific characteristics of flexibility and hardness. This is blended to food grade paraffin wax to give a more flexible wax for coating.

Take care if you're experimenting though!

Anne Miller wrote:Steven, this is a no longer recommended method. Over time, paraffin wax shrinks and expands with temperature changes leaving the jam and jelly susceptible to growth of molds and yeasts

Thanks for that. In my memory I thought the seniors Were using the boiling bath method, but apparently not!

Steven Lindsay wrote: Were using the boiling bath method, but apparently not!

I am not sure what you mean.

This is from the link above:

Use a water bath or pressure canner, as appropriate to the recipe.That simply means immersing the sealed jars in boiling water (or in a pressure canner) for the time required in the recipe.  The recipe will explicitly state which canner to use.
Do not modify recipes, except as they explicitly state you may.