I used plastic film for calking. I used this method when i was building "Carolina". All that one needs for this can be found in any stationary shop.Lovely build. What did you use for the deck caulking?
Plastic bag for paper (they can be found in different colors and thickness) and two sides adhesive duct tape. I
use the balck side of the plastic bag. I put the duct tape on plastic fim and cut it in stripes according to the thickness of the batten,
it can be made with a small margin, then I separate
protective paper from the strip and stick on the end of the batten, the allowances are cut off with the knife, - it's cutting off nicely.
Here are several photos, maybe they can be of use to somebody. If you have any questions - it would be my pleasure to help.