Although nothing wrong with doing planking with a pen, its basically the same as the way the planks are lazer printed, only one issues if u mess up and slip you will have a mark or line that shouldn't be there, this is either extremely difficult to remove or worse case results in starting again and scrapping the piece.
I have a method that works quite well for me ( no photo's as yet, but keep watch on my Komet Build Log it will be demonstrated there as the printed deck sucks and will spoil the models finish, its a nice model shame to spoil it with a printed deck)
I have a Router part for my dremel and a 1mm engraving bit, simple using the router guide which can be set for distances as deep as 300mm (so i can cover most deck sizes from either port or starboard,) and run the router down the edge of the deck and engrave a groove down the deck, ( the depth is set by the router parts depth gauge) move the router in by the thickness of the plank and repeat process until jobs done.
This will work for any curves and straight line parts, but it won't do complex patterns or 'cut in's'
Now to get your 'caulking' effect my method (one of my favorites) is to use black cotton thread and pva glue, run a very thin bead of glue down each grove ( i use a paint brush) now take the black cotton and slowly push it into the groove,( don't have to keep the cotton taught so don't worry)
Once all the groves are done let the deck dry for a day or so, then sand the deck down start with 120 grit and work your way to a smooth finish.
You can now either Stain the deck ( this will not effect the cotton) and varnish, or oil it and use some polishing wax to protect the surface or give a particular finish .
Anyway this is one method i like using other then that its the old fashioned way... single planks my next favorite method.
Hope it helps Kenny