In very general terms -
A sporran of all leather, with a flap in front - is usually called a day wear sporran.
If you retain the flap but the front is fur - it is called by some a semi-dress or semi - formal sporran.
If all fur with a half round metal cantle opening - it is usually called a formal sporran.
Half way between semi formal and formal are the Hunter style. (Called 'Hunter' because the tassels are sewn down so don't make noise.)
All leather with a cantle opening.
Also in general terms a bright cantle is considered more formal than a leather cantle.
And still in general terms black is considered more formal than brown.
The horse hair sporrans are usually thought of as for pipe and drum majors and the military.
A leather sporran strap is usually seen for less formal or day wear.
And a strap with a chain or fancy links is thought of as more formal.
Sporran suspenders are really helpful for guys with a bit of a belly as they hang from the belt and have less of a tendency to pucker the apron under the belly.
Tassels on chain are usually considered more formal that tassels on leather.
What it all comes down to is bling. The more bling - the more formal.
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