If you have a marble or granite slab or work surface, grease it liberally; grease a palette knife also.
In a small jug place 1 tablespoon of water and sprinkle in the gelatine. Leave to soak.
In a heavy based saucepan put the sugar, 4 tablespoons water and glucose syrup, if using. Heat over a medium heat until sugar has dissolved, stirring gently.
When the sugar mixture comes to the boil continue to boil for 2 to 3 minutes or until the syrup has reached soft ball stage on a sugar thermometer.
While the sugar is boiling heat the soaked gelatine in a saucepan of simmering water until dissolved and liquid.
When the sugar has finished cooking remove from heat and dip the saucepan's base in cold water to halt cooking. Leave to cool for a few seconds.
Add the gelatine and glycerine, if using, to the sugar then stir gently to combine.
Pour the mixture out onto the marble slab and begin turning and mixing with the palette knife until it becomes clay-like. Be sure to mix and knead well. At first, the fondant will be very fluid, but it will gradually harden. After 5 to 10 minutes of turning and mixing, the fondant will become very stiff, crumbly and hard to manipulate. At this point, lightly grease your hands and work surface, and begin kneading the fondant into a ball as you would with bread dough. As you knead, the fondant will begin to come together and become softer and smoother. Stop kneading once your fondant is a smooth ball without lumps.
Put the fondant in a sandwich bag or wrap in plastic wrap and refrigerate overnight or at least a few hours; until set.