Stop using your finger to seal your painters tape, the pros are using the cobber.
The cobber easily fits in your hand with your index finger at the tip of the tool where you apply pressure to your masking tape to get a 100% seal on your tape to stop the paint from seeping under your tape. The other method used to seal your tape is with your finger which gives you only about a 50% seal on your masking tape, this is how the paint bleeds.
-Areas we use the cobber after applying masking tape & before we start any painting-
Walls & ceilings
Inside corners before painting accent colors
Basically every surface you tape you must have a 100% seal on your painters tape before you start painting or you will have a mess to clean-up or touch-up from paint bleed.
This is a trick the pros don’t want you to know.