The superlines are very slick and will spin on the spool if you don't use tape or a mono backing. Most people I know that use tape use electical tape. I prefer using a mono backing and just tying a uni/uni knot to join the two lines.
Hello BOBHUNTDEER: Instead of tape first put on some mono line than tie the fireline to it. The reason is the Fireline is alway dry and it will just spin on the spool and you won't be able to wind it up when you have a fish on. See fireline is so hard it won't grip the spool for traction. I've been using fireline since we could buy it here in Michigan and it's all i use on all my outfits. Make sure the line guide's are NOT ceramic as it will cut into it for sure. Any questions please ask me.