Having a paper map is great until the weather becomes bad enough you actually need it. More often than not that is when it becomes a sodden mess. Map cases are good but if you do not want to buy a case you have a number of options:
a) buy a laminated map. They cost more but last longer and don’t need a case through the summer
b) buy a paper map and cut the section you want out and laminate that yourself. The main drawback with this is you use a map just for one walk
c) use something like Memory Map on the internet, print the route off and then laminate it
As instructors on the Torridon Activities team, we use a mixture of these options. Because we walk on the same hills often, we already have a selection of maps printed and laminated. During winter, we always put our maps into a case whether they are laminated or not. This is because ice often forms on the laminate and it can become slippery in wet and cold conditions.
When it comes to cases, I would recommend one that can hold an A4 sheet comfortably and before you set off, we recommend you fold the map to display the walk you are on. The last things you want when it is raining, snowing and windy is to pull out your map and try to fold it into place in the teeth of the Highland elements!