If you plan to make a ghillie suit, you will need supplies, time, effort, and patience. Depending on the purpose of the suit, as well as the quality and longevity you want from the finished product, you may spend many hours preparing, making, and seasoning it before you can put it to use. When a ghillie suit is made from scratch, these tasks can take as many as 100 hours to complete. For a small cost, however, you can buy most of the materials you need to put your camouflage together more quickly and easily. A third option is to buy a ghillie suit that is pre-made and ready to wear.

A ghillie suit starts with a foundation, usually a battle dress uniform (BDU) comprising pants and jacket, a flight suit, or simply an old pair of coveralls. If you improvise your own foundation suit by using such garments as old coveralls, make sure they are first washed with a detergent that has no scented chemicals added. When you need your ghillie suit to provide cover only from the waist up, leaving your legs free for movement, you can plan to make a net poncho covered with ghillie material rather than a full suit.

Dedicated people who are determined to make their own ghillie suits from scratch need to buy burlap in preparation for the most time-consuming and tedious part of the operation. This involves dyeing the burlap to various shades ranging from medium green to brown, cutting it into strips, and sewing the strips onto the foundation suit with the ends of the higher strips overlapping the attachment points of the lower strips by about half an inch to provide coverage. Alternatively, you can first sew and glue netting to the foundation suit, then attach the dyed burlap strips or jute twine to the netting. Be careful not to finish with blocks of strips in similar coloring, as this will defeat the aim of using the ghillie suit to merge into the background.

The dye colors should be chosen to blend in with the area where you will be wearing your ghillie suit. You can also increase the authentic look by taking the suit to the area and rolling it around in the local vegetation, or by adding some of the vegetation to the strips on the netting or the suit. Keep in mind, however, when making your ghillie suit, that burlap is hot and heavy. If you add too much to it, you may find it difficult to move as quickly as you may need, as well as being uncomfortable, particularly in hot weather.

You can omit the dyeing and cutting, but still have a hand in the making of your ghillie suit by buying a ghillie kit that includes all the materials you need, as well as assembly instructions. These can be ordered in the custom color combination you want or bought in available patterns, and can take from five to 10 hours to complete by hand. If time is a factor, a pre-made ghillie suit costs more than a kit, but saves time and effort.

When making your own ghillie suit, you need to remember that Hessian and burlap are highly inflammable and take appropriate precautions to treat it. This need should not apply to the ghillie suits and kits available for purchase, because they are usually treated with fire retardants before you buy them or are made of fire resistant materials. They are also often made of materials that are lighter and cooler than burlap, making them more comfortable, if less traditional, than the type of ghillie suit you would make yourself.

Tyler is a manager at Ghillie-Suit.net. The company features a wide selection of ghillie suits and ghillie kits for hunting, paintball, and the military.

cold air falls and warm air rises. Why? Discuss!

Many of us experience the effects of falling cold air and rising warm air on a regular basis. It is happening all the time in the air above and around us and is one of the components in our weather systems. You may notice that when there is no heating or air conditioning operating in your house, the rooms upstairs are slightly warmer than those downstairs. Another example is the hot air balloon that works precisely to this principle. By heating the air inside the balloon, the craft will be lighter than the surrounding air and will rise. This is actually the result of cold air gushing downwards around the balloon at the same time as it is rising.

So why does cold air fall? That is simple: it is heavier than warm air. And why is it heavier? That is slightly less simple, but only slightly. As with any gas, the air (a generic term for the mixture of the gasses in our atmosphere), contains molecules that move (or agitate). This movement (or agitation) is greater as the temperature rises. The molecules move in ever greater orbits, taking up more space. This causes the mass of the air to expand. Although the total mass of a lump of air has not changed, the mass is more spread out and so any given cubic area of it will be lighter. An analogy is found with popcorn. A half pound of popcorn before being popped may fit into a cup. After popping, the same corn would fill a large saucepan. Its total weight will be more or less the same half pound that it always was, but if you filled up the original cup with the popped corn, it would weigh less than the unpopped corn as the rest of it would no longer fit into the cup. Expanding hot air is similar. A cup of cold air would weigh more than a cup of hot air.

As we are playing the why game, let's continue. Why do the molecules move about more when it is warmer? They absorb energy through electro-magnetic waves that smash into the molecules. In short, this is energy transfer by radiation. So we have a collection (several trillion, lets say) of molecules that are very agitated and another collection which are far less agitated. The agitated collection is spread out and thus light. The collection that are less agitated is heavier. The heavier stuff falls downwards, while the light stuff rises.

As well as being the main process behind hot air balloons, the movement of air according to its temperature is a critical factor with the weather. Forecasters must ensure that these movements are factored into their modelling systems in order to produce a decent weather forecast. Air conditioning designers and must also take these factors into account as must architects. In order to preserve valuable heat, warm air must be prevented from escaping through the top of a building. As well as conserving heat, the movement of colder air downwards must also be considered when designing refrigerators and refrigeration systems.

If you have a few minutes, try this experiment. Firstly make sure nothing has been put into your refrigerator for at least 2 hours. Then, leave a thermometer inside the refrigerator, making sure it is placed at the bottom and then close the door. After 10 minutes, open the door and straight away and note the reading on the thermometer. Then place the thermometer on the top shelf and close the door. After 10 minutes, take the reading as soon as you open the door. You will notice a difference - perhaps as much as 1 to 2 degrees. This may not be such a big issue for us at home most of the time. For commercial kitchens, however, this difference maybe critical when ensuring food is kept at an optimum temperature. Commercial fridges are often fitted with a fan that evens out the colder and warmer air, thus negating the tendency for cold air to fall and warmer air to rise.

If you take large freezer stores - the ones that hold thousands of boxes of stock - the movement of air around the facility is an extremely important factor. The fans that blow frozen air into the store are always situated near to the ceiling, allowing it to diffuse downwards. Eventually, of course, the goods in the freezer store will need to be taken out and moved to another location, typically loaded onto a truck. If frozen goods are loaded onto a frozen truck this is no problem. Occasionally though, only a small quantity of frozen goods may be needed and the use of a large truck whose temperature is set at a frozen temperature would be wasteful if only a few boxes were being despatched. This is where insulated pallet shrouds or roll cage covers come into play. These enclose the pallet or roll cage, protecting frozen goods for up to 8 hours within an ambient environment (they also protect ambient goods such bakery products and bananas in a chilled or frozen environment). When a roll cage is used, the insulated roll cage cover works at its best when the cage is full of products. When it is half full then - you guessed it - the cold air falls to the bottom. This is fine at first (assuming the goods are in the bottom half), but after a while the warmer air that has risen to the top will start to affect the top layer of goods. This is where a temperature insulated divider must be used to make a seal and protect the goods in the half full roll cage.

So now you know the whys and hows of cold and warm air and now you also know why your feet get cold in winter!

Vernon Stent is the content writer for 5es.co.uk, where you can purchase or rent roll cage insulation covers and dividers and pallet covers.