You can also try an edger, similar to:

https://www.homedepot.com/p/Shur-Line-4-75-in-x-3-75-in-Edger-Pro-2006561/202080280

It takes a bit of practice, and the secret is using minimal paint to avoid getting it on the rollers or anyplace other than the pad.

A professional painter would be aghast at something like this, but probably not quite as much as using tape. :-)

Tape and similar masking products are more useful when you're doing spray-painting.

Your specific results look like the paint isn't bonding to the drywall and just drying as a "layer", so the bond to itself (and the tape) is stronger. I'm most definitely not a professional painter, but I think that's the bigger problem to solve in order to get decent long-term results.

3M Scotch Delicate Surface Painter’s Tape, it usually has an orange core.

If the paint stills comes off like that, then I agree there's a bigger adhesion, possibly curing issue.

Thanks all. I did put a dilute coat on the drywall first, as its new. Perhaps I should have done more than 1 coat?

i think masking tape is too sticky and harsh. I would use frog tape or painters blue only. Also, you should pull it off within an hour or two, definitely not the next day.

No tape. Buy a good paint brush (e.g. Purdy) and cutting in is easy unless you have particularly unsteady hands.

I use blue painters tape and pull it off as soon as you finish that area, while it is still wet. That works well on trim. Where there is no wood trim I just use a brush and hope no one gets a ladder to look at it.

Brad, thanks you. Here's a video of me very sadly scraping the lovely Benjamin Moore paint from our wall in an area I'd knocked previously. Do you, or any other of you wonderful folk know if the paint looks like it's adhered ok to the new drywall beneath which I'd painted first with a very dilute water/paint mix? Thank you again!

are you putting tape on a newly painted wall? Im pretty sure the tape says you cannot do that. It has to cure for 30 days first.

which I'd painted first with a very dilute water/paint mix?

1. Why did you do that?

2. Why are you taking a putty knife to it? No paint bond/finish is going to withstand that kind of aggressive scraping with a metal edge.

The 'mist coat' is to allow the new drywall to absorb the more dilute mix so that the paint adheres to it. It's naturally absorbent and so if you paint on to it without doing this then the paint flakes or forms a skin. The example with the scraping was to garner opinion as to whether this was what normal paint would do or if it appeared to be more in keeping with paint which hadn't properly bonded.

Are you using a primer coat before the paint? I think new drywall really needs it.

And if you use blue painter's tape, don't put it on a painted surface for at least a few days (a week or more is better), and remove it shortly after finishing the section, while your new coat of paint is still wet.

Don't use tape at all. Use an angled brush to cut in walls after the ceiling has been painted. It helps to run a lead pencil around the room where the walls meet the ceiling. Just put the pencil point in the corner and run it around the room. Then just cover the pencil line with your brush when cutting in the walls. The pencil trick gives me a neat, clean line where the wall paint meets the ceiling paint.

When painting on new drywall, I use a Dunn Edwards primer specifically for new drywall.

Whenever I do use painters tape for anything, I remove it as soon as I'm done putting on the coat of paint, while the paint is still wet.

New drywall, needs a primer on it, that is meant for new drywall, and then 2 coats of regular (not diluted paint on top of that. I would learn to cut in (watch some utube videos), they should help you a lot. I use Delicate use yellow frog tape, if there is somewhere I need to tape. Never on a ceiling. Learning to cut in your paint, will save you a lot of tape, and a lot of time..

The tape you are using is a high adhesion tape. In addition to the great suggestions above, keep in mind that the tape you chose is for use on concrete, carpet, etc. I'm not sure any paint surface could handle having this tape applied and pulled up, without bringing the paint/primer along with it.

Use painters blue tape if you have to use tape. Remove no more than an hour after you finished painting.

I know if you google there are plenty of you-tube painting tutorials.

No idea what you are trying to show in that video?

How long ago did you paint your ceiling? I am one who prefers to use tape (green frog tape)...but you can't stick it on paint that hasn't cured yet.

Like others have suggested, skip the tape and use a special brush for cutting, a $20-ish Purdy brush would work perfectly (will save you time and money in the long run).

Professional painters don't use tape, you'll see them cutting first and then rolling the rest; unless they're lazy and use sprayers.

PS. Never dilute paints, they're supposed to be applied undiluted; not even for a primer.

If new drywall is not primed, this is what can happen when you use tape on it.

Thanks so much all for your responses wonderful people, I'll use your advice!

I'm not a good enough painter to not need painters tape. FrogTape Multi-Surface is great.