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3M's Mobile Phone Privacy Filter

At this year's InfoSecurity Europe I visited the 3M stand again to see what developments they had for their privacy filters. They had their excellent Gold filter there of course, which is now properly on sale in the UK and the best on the market in my opinion. I previously blogged about this filter in my post "Why do I need a privacy filter? (3M's new Vikuiti Gold Privacy Filter)".

So what's this blog post about? Well, they have now produced privacy filters for mobile phones. Let's add a bit of context to this decision. How many businesses provide mobile devices to their employees that are connected to the corporate network with access to email, contacts, calendars and corporate documents? If you were reading an email from a client or reviewing a sensitive document would you be happy for someone to peer over your shoulder? Maybe you're paranoid like me and try to avoid reading emails in public places and stand with your back to the wall, shielding the screen when you have to read something urgently (Note: you shouldn't really store sensitive documents on a mobile phone in the first place, but that's another topic). However, 3M have made the whole thing a bit easier and allowed people to look a bit more normal than I do when using email in a public place.

I had a bunch of questions that I wanted to ask 3M about this new filter and I got some answers that I will share with you here. Firstly, I'll give you a brief introduction to their product, which can be seen in the image below. This is basically a screen protector with the privacy filter combined. It uses the standard matte grey louvered filter that gives privacy in one plane (I'll explain this in a bit and the problem with it). It uses the matte film as reflective films would get scratched with the type of use that a mobile gets according to the guys on the stand. The film is self-adhesive, using 3M's Post-It note glue, so it should come off with no residue and be easy to fit. This is effectively a replacement for your standard screen protector with the added benefit of including the privacy filter.

3M's new mobile privacy filter

Now to some of the questions I had:
  • Does it work with touch screens? - Yes it does. They had an iPhone there and it worked perfectly.
  • Does it work with a stylus? - Yes it does. They had an Windows Mobile-based XDA there, which also worked with no problems.
  • Does it make the mobile hard to use? - No, the dimming of the screen caused by the filter is not too much of a problem. With the backlight off you pretty much can't read the screen, but how many people use their mobile with the backlight off? There is some drop in brightness, but you can increase the brightness of the screen to compensate. However, this does have the big side-effect of reducing battery life - a major problem on smartphones.
  • What if I have a mobile that I can use in landscape as well as portrait, like an HTC or iPhone? - Well, you have a problem. It comes back to what I said above: the filter only works in one plane. The filter has vertical louvres so that as you move to the side they overlap and block out the screen, like vertical blinds. However, vertical movement doesn't change the overlap of the louvres, so there is no blocking of the screen in this plane. So, you have to decide which way you want the filter, portrait or landscape - it will only provide privacy in one plane. Now, this isn't a problem for a lot of phones, particularly the majority of Blackberries, which are still the preferred business machine by many organisations. It is a problem, however, for iPhones (which aren't business phones in my opinion) and many Windows Mobile phones with the iPhone-esque interface.
  • Couldn't we have the Gold filter on a mobile to sort this problem? - Unfortunately, not yet, but they are working on it. There are a few technical difficulties apparently. Firstly, there is the point I made earlier, that mirror finished filters would scratch too readily on a mobile device that is thrown in a bag or stuffed into a pocket with other things. Apparently, they have a matte version of the Gold Filter in the lab, but it isn't available yet or in the near future. There is a second problem. Apparently, the Gold Filter doesn't take to being glued so easily as the grey filter. However, they are working on this as well and hope to have a solution soon.
  • Do they come pre-cut to my mobile? - Yes and no. If you have a Blackberry or iPhone then yes, otherwise no. You buy a sheet and cut it yourself. I believe that there are other companies, such as, that will be able to cut one for your device in the future. I think this is a must for the uptake of the filter. How many business executives are going to sit down with a craft knife and straight-edge to cut their filter to the exact shape and size of their phone as well as the holes for the buttons, cameras, speakers, microphones, etc.? The problem for 3M is that mobiles come in all shapes and sizes, with absolutely no standardisation. Laptops and monitors, on the other hand, do have standard sizes.
What's my verdict? Another good product from 3M. I think this would be very good for executives with the Blackberry-type device and still help those with touchy-feely, accelerometer-driven interfaces, as long as they remember to only access sensitive information in one plane. They will have a great product when they get the matte Gold filter stuck to the mobile.


  1. now a days it is good to protect mobile phone by privacy protector and it works properly

  2. Mobile privacy filters and screen protectors are really useful..thanks for sharing this useful information..Business phones

  3. This comment has been removed by a blog administrator.

  4. Your post is very easy to understand,I will share it with my friends. Hope there will be more good posts here...
    Phones Systems

  5. After using the filter for a month now, I can reflect in more detail on the system. The solution for holding the filter to the screen is absolute crap.


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