You want to leave whatever gap the manufacturer recomends, usually 1/8" to 1/4" depending on the size of the area. I cannot see this looking the least bit professional if you are not going to hide the gaps. If 1/4 round is not an option, then you really should remove the existing base, under-cut your door jambs, then reinstall the base after the floor is down. If the base cannot be removed, then under-cut it all. If you insist on leaving the gaps, (which quite frankly, will look horrible) find caulk that will match before you start. "Test caulk" a piece or two against your base and let it dry over night, to make sure you get the desired look, hopefully you will realize how bad it looks. Buy some extra caulk, because you will have to re-caulk ocassionally. As the floor expands and contracts with the seasons, it will eventually pull away. If you go the caulk route, (and I really hope you don't) you can use pattern felt and scribe to keep a consistent gap. Again, this caulk route will look very, very, very bad, and will certainly take away from the beauty of your trim.
Again, this caulk route will look very, very, very bad, and will certainly take away from the beauty of your trim.
Again, this caulk route will look very, very, very bad, and will certainly take away from the beauty of your trim.
Would really like to see pictures of this trim.