This is my first working setup, done in a rental friendly way without drilling. I am sure that it is possible to do it cheaper, better and with less work, but it the first one that worked for me, so I will document it.
Cost: 150 Dollars for a relatively large 130 x 158 cm window. They do not sell for windows much larger than that.
Bought from www.orderblinds.co.uk on June 2019.
My window faces East, and in summer the sun rises at around 5AM here, and I am a bit light sensitive and was getting destroyed.
This setup, together with:
is good enough to allow me to sleep properly, which is priceless.
Figure 1.
Total Blackout Cassette Roller Blind With Curtains.
Source.
Figure 2.
GO Travel sleeping mask
. Source.
Demonstration if everything goes exceptionally well:
Video 1.
How to fit a Total Blackout Cassette Roller Blind by Order Blinds Online (2016)
Source. The actual product name appears to be Bloc Blinds or BlocOut, Order Blinds appears to whitelabel them.
However, not all will necessarily be fun and games as in that YouTube video, especially if you are doing it for the first time, and the main point of this article is to make you aware of that.
The first problem is that you may have to remove existing useless "privacy blinds" from the way, which can mean putting effort into learning how they work and, has a risk of damaging the property. So be smart and get a chair and a second person to help you out!
Next, fitting the side rails is not going to be that easy. The thing has to be tight to block the light, right? Careful not to scratch the bottom sill!
Then you will notice that, like in the video at youtu.be/cTVVe7codw4?t=106, you are expected to screw the side rails to the bottom wood / plastic sill of the window, which is not rental acceptable! So I didn't to that, but together with the black tape that I will mention next, it held well enough.
The top part requires hammering nails as shown on the video: youtu.be/cTVVe7codw4?t=24 but this is generally rental acceptable, and you can fill the holes afterwards.
Once you have the setup in place, it is likely that there will be some light gaps still, because it is basically impossible to make such large objects fit perfectly. This was especially true for the top of the window, but also for the sides, so I just used some black tape
So I added some wide (50mm) Figure 4. "Diall PVC repairing black tape" between the blind and the wall to completely seal off the light.
Figure 3.
Total Blackout Cassette Roller Blind Black Tape.
Source.
Figure 4.
Diall PVC repairing black tape
. Source. This tape made things dark and was durable, but note at Section "Removal wall damage review" that it pulled bits of the plaster out with it during removal. I've since learnt about the existence of "painter’s tape"/masking tape, that might have been a better idea to protect the walls when pulling the tape off. It is worth noting that some of the painter's tape do come with a maximum number of days before you can pull them off, presumably after which wall damage becomes a possibility, e.g. Ciro saw one rateed 14 days.
There is still some leakage at the bottom however, which cannot be taped. I mitigated that a bit by putting some black T-shirts on the bottom window sill, and together with the pre-existing rental curtain, it was enough.
Another minor annoyance is that parts of the blind cloth sometimes slip out of the conduit holes in the aluminium side bars. For this reason, I have to always open and close slowly and carefully. But if it does happen, fully opening and closing carefully has solved the problem.