Heavy, just go to Home Depot (or similar store) and buy a roll of the "aluminum foil" tape. $5. You know you have the right stuff if you can see yourself in the reflection from it. Don't use other reflective types of tape, because they will not be as effecient in reflectiving the maximum amount of light out.
I did my turn signals with this stuff and they do seem brighter. I can't justify buying new turn signals just for this, or even brighter bulbs because of other issues such as your wattage limit, etc. involved.
The only drawback is it's a pain to cut the pieces to fit in the housings.
'06 DL1000 - Grey
'89 GSXR 1100
'85 GS550E (Suz)
'75 Yamaha MX250B
'73 Yamaha MX125
Keep your feet on the pegs and your hand on the throttle.