Bead base: opaque or transparent combinations

[stardrift]

As a very beginner, I have been reading as much information as I can about techniques.

I have read someplace (heaven knows where) 'that a new person' at the torch should stick with the following combinations to have a more successful turn out before moving onto other techniques or combinations.

Can someone explain the reasons to use the following combinations:

Opaque on opaque, transparent on transparent or transparent on opaque.

Is it to do with heat retention?

Thanks!

[Three Muses Glass]

I'd say more like heat control. Transparents are a bit stiffer than most opaques. Take dark ivory for example. It can be the soupiest glass when you super-heat it trying to get certain effects. Like almost falling off the mandrel onto your bench soupy. Learn to control that, and you'll be well on your way to learning the heat control for any of the soft glasses. Transparent glass is stiffer and I guess easier to work with for beginners.
I can't say what those particular combinations in your post would be for, but any practice is good practice. You'll learn which glass spreads, which ones get swallowed up, which ones have reactions....

[SadiesJewels]

Sometimes stringer control is practised with the same color as the stringer as is the base. If you mess up you simply melt the stringer back in (practise rounding out the bead again) and start over. It can be done with opaque on opaque or transparent on transparent.

[honey*bee]

In Corina's Stringer Control DVD she also says that when applying raised stringer detail you have less risk of the decor breaking off if the stringer is the same as the base (trans on trans or opaque on opaque).