Monthly Archives: August 2011

We think that eTray laptop trays are special for a number of reasons. One reason is that they are the only beanbag laptop trays we are aware of that are purpose designed for laptop computing.

Another is that they are available in different sizes to suit different sized laptops and to take account of the different ways that you might want to use them.

There is also the wide (and growing) range of designs and colours that you can choose from.

But, perhaps the most important reason that they are special is the amount of care that we put into making them.

We use the best materials that we can obtain, and these are careful assembled and hand finished to provide a product that is beautiful and tough enough to survive daily use for years.  All eTrays come with a one year warranty, but our intention is that you should have them for life.

All eTrays are made using a step by step process that starts by selecting the materials that are to be used and ends with the completed eTray ready for shipping.

Three main parts

eTrays are made from three main components; a frame, the laminated deck that the laptop sits on and the bean bag assembly that fits under the deck. Let us start with the first of these.

Building the frame

We make use of the same general formula that picture framer’s have used for years to produce our frames. Four lengths of frame material are cut with 45 degree bevels and these are glued and butt jointed together with stainless steel “V” nails.

Making the deck

An eTray deck fulfils three purposes:

  • It provides a flat surface for the laptop to sit on. This is important because it allows air to flow freely underneath the machine and that allows the machine’s cooling system to operate properly.
  • It provides a surface for the mouse to operate on. This needs to be both durable and must provide a texture that optical mouse can “see” so they operate properly.
  • It acts as both insulation and shield to reduce the transmission of heat and electromagnetic radiation between you and your laptop.

To make the deck we use rigid high quality MDF board with an aluminium foil shield panel attached to the underside. We use a wide format printer loaded with archive grade ink and high quality photo paper to produce the ink jet prints that go on top of the MDF panels. close up of etray mousing material

These are laminated with a finely textured vinyl laminating film before being fixed to the deck using a low-acid photo mount adhesive.

Sewing the beanbag

The bean bag that fits to the base of an eTray is made of fabric attached to a sheet of card which is used to attach the bag to the base of the tray. The corners and the overlapping adge must be sewn with great accuracy.

Once the bag is sewn it can then be filled with expanded polystyrene beads. The exact amount required varies with the different size trays, but it is important to get the right amount. If we add too much then the tray won’t sit on your lap correctly and the whole thing can become unstable. Too little and you lose the insulating effect from the polystyrene beads.

Putting it all together

Once we have all three component parts available, the next step is to assemble them to make a completed lap tray. We start by fitting the deck to the frame.eTray deck glue

We trim the edge of the laminate so that it is a slightly loose fit in the frame. This allows some room for heat expansion.

The deck is bonded to the frame around its entire circumference with a specialist glue. This last stage is very important because it is this that give an eTray is characteristic solid feel, and also helps makes them extremely durable.

To fix the bag we apply hot melt adhesive around the edge of the deck  to bond the bag firmly into place.A finished etrayAfter a careful inspection the eTray is now completed, ready to be packaged for shipping.

According to The Register, a condition called “Laptop Computer Induced Erythema ab Igne”) is now causing concern amongst medical researchers. Erythema ab Igne is more commonly known as Toasted Skin Syndrome – the term used to describe the blotchy red areas that can appear on the skin after exposing it to heat for long periods.

In this case it is caused by the sufferers using their laptop computers directly on their laps for a long periods of time.

These blotches can get very itchy and they are undoubtedly ugly, but the main concern is that the discolouration may be permanent. Also, it is not clear if there may be other long term problems such as an increased risk of skin cancer as a result. eTray laptop tray keep you cool

There seems to be some fuss about it at the moment, but it is not a new problem, and we have been concerned about it for some time. Toasted skin syndrome is just one of a number of potential health issues that are caused by using laptops computers in this way.

The obvious way to avoid the problem is to put some separation between yourself and the laptop, and I can think of no better way to do that than by making use of an eTray laptop tray. The eTray will protect you from the heat of the laptop and will also put you in the correct ergonomic position  so that you avoid back and neck strain.

When you get up after a long session of using your laptop how do you feel?

Stiff neck? Achy shoulders? Twinges in your lower back?

These are all signs that your laptop, or rather the way that you are using it, is hurting you. If you keep on using it that way there is a risk that those aches and pains will turn in to a permanent injury. Fortunately, it is easy to avoid the problem by making a few small changes in the way that you use your machine. Read on to find out how.

Laptop ergonomics

From an ergonomics point of view, using a laptop on your lap is close to the ideal thing to do. The position allows you to recline slightly and this means that, with your hands comfortably on the keyboard, your head and neck are in a naturally comfortable and relaxed position.

Contrast this with what happens when you put your laptop on a standard height desktop. You have to sit forward and, with your hands on the keyboard, usually need to duck down to see the screen clearly. Sitting forward is bad for your back anyway, but the added distortion involved in ducking down means you could be setting yourself up for some real problems in the long-term. Ouch!

Three big problems

So, using your laptop on your lap is the best thing you can do from a back health point of view, but doing this does present some problems. I think I could go on expanding this list for some time, but here are three immediate examples:

Bottom view of an Acer laptop showing the cooling system intake

  1. As soon as you set your laptop down on the top of your legs you will most likely block off the air intake grills (2) to your machines cooling system. Starved of air, the machine will quickly overheat. This threatens to cause actual damage to the electronic components inside the laptop, but before this happens it is more likely that it will become so hot that you will be forced to remove it.
  2. Putting a laptop on your lap means adopting a knees together posture that causes another potential problem for men. We are just not built to spend time sitting this way, and it has been suggested that local overheating could damage male fertility.
  3. Laptop computers are a source of electromagnetic radiation at a wide range of frequencies. Modern machines operate at around the same frequency as your microwave oven does and they have built in radio transmitters for wifi and Bluetooth. None of the machines I have examined have had any significant shielding, and it is common to locate the wifi antennae right at the bottom of the machine. There is no evidence that these signals are strong enough to cause any harm whatsoever, but some experts think it is wise to work on the precautionary principle and I am inclined to agree.

Do not leave the bottom of your MacBook Pro in contact with your lap or any surface of your body for extended periods. Prolonged contact with your body could cause discomfort and potentially a burn.

Apple MacBook Pro Manual

So, what is the solution?

eTray laptop tray with Acer laptopWell I guess you must realise at this point that I am probably going to say to you that you should get yourself an eTray laptop tray. Its true, I am going to suggest that, but eTrays are not the only solution so I should explain what I think you should be looking for.

The worst thing you can do is to insert a cushion or similar between you and the machine to provide some insulation. The air intake will still be blacked and the overheating will continue, but now you won’t be aware that is happening until it is too late. If the machines does get damaged you might find that the manufacturer is reluctant to honour the warranty and that might mean a very expensive repair bill.

Nor do you need to buy an elaborate gadget with built in fans. The laptop’s cooling system will work just fine on its own as long as you keep the ventilation slots clear. The fans are noisy and require power from somewhere to work. That usually means you have to plug them in to a USB port where they will take power from your machine’s battery. Even if you are running off the mains adapter that will cause additional heating, and there if there is any benefit this will most likely neutralize it.

The laptop needs to be placed on a flat surface so that its feet can maintain a clearance (usually only 3 or 3 mm is required) that will allow cool air to reach the intake grill. Nothing more is required to keep the machine happy, so you could use a piece of plywood or MDF, or even a large book and you would have a solution. If you use one that is big enough then you will have space for the laptop and room for a mouse.

Of course using a board in this way is going to get a little uncomfortable after a while and the machine will still produce some heat in normal operation. Putting a cushion of some kind under the board will make it more comfortable and provide some insulation from the machine.

The question of what to do about electromagnetic waves is a bit more complicated and needs some explanation. The problem and solution are summed up pretty exactly by the old phrase “you need a long spoon if you are going to sup with the devil”. Electromagnetic waves obey what is known as the inverse square law, which simply means that the amount of energy they contain reduces considerably with distance. You will never get completely away from them if you use computer equipment, but you can reduce your exposure by adding some distance.

Even short distances make a considerable difference and the spacing you introduced by putting a cushion under the board will have reduced your exposure considerably. You can reduce it even further by introducing some shielding that will reflect electromagnetic waves.

Cross section of eTray laptop tray showing the main components

For eTray we use a sheet of heavy duty aluminium foil which is located directly under the centre of where the laptop will sit. It’s not a complete solution, but it will reduce heat transfer and interrupts the direct path for wi-fi signals between your notebook and your lap. You can get a similar effect with something as simple as kitchen foil.


Custom eTray designWe often get asked if we can produce custom eTray laptop trays, personalized  using photographs uploaded to us.

The answer is always yes – we can do that. And we are not limited to digital photographs. We can print any kind of digital artwork including cartoons, company logos, line drawings, or scanned images.

To order a personalized eTray from the web site go to: to order your custom tray directly from the web site.

If you have any questions or need information about  the technical details of the process go to:

Do you want a number of eTrays?

Incidentally, if you are interested in having several eTrays of the same design we may be able to give a quantity discount. Let me know which eTray size you want, and the quantity required, and I will provide you with a quotation.