I use a 13g packet of food gelatine to 500ml water. I let it bloom for 1/2 hour or so in cold water then use a bain marie and bring it up to 60-70 deg C adding 50ml methanol. Hardener (formaldehyde) goes in just before I size. I coat with a foam brush. I only get sparklies on the outside edge, where sized and unsized paper meet.