You generally have two choices when printing on paper. Besides from the thickness of the paper, you can basically choose matt or gloss paper. Occasionally, printing is done on coloured paper but your local printer will not hold a lot of different paper stock except for the variations in thickness.
The opposite is true for printed labels. There are simply many variations when it comes to the type of stock used. Bumper stickers, packaging labels, product labels for frozen goods, labels on windows and the simple labels on envelopes or paper all use different substrates or paper.
If a label is required for indoor use and has no requirement to be protected by liquids or weather, then simple paper labels will suffice. Regular self adhesive label stock is used. Gloss label stock is the most common because it enables the labels to stand out on its shiny surface. The colours can be made even more prominent with a laminated finish. This has the added advantage of protecting the colour printing on the labels for a longer period of time than otherwise would be the case without lamination.
There is also the option of using matt label stock. These types of labels are less popular than gloss label stock because the finish is much duller. The great advantage of matt label stock is that the labels can be easily written on and this is sometimes necessary for storage and additional documentation.
As with general printing, there is also the option of using coloured paper. Fluorescent label stock in colours such as red, orange, yellow, green or pink will enable products or boxes to stand out even though the labels are simply printed in black rather than colour. The coloured paper is more expensive than regular white label stock but the cost of fluorescent labels is not inhibitive because typically only black printing is needed as the background colour really makes these labels stand out. Often, warning labels and other types of packaging labels use fluorescent label stock. Black printing on red fluorescent or radiant paper is the most common option. Red indicates warning but yellow and orange are also strong colours.
Metallic label stock is less common still but still has its function. This metallic label stock, almost always, silver or gold, can make a label appear really classy. It is a bit more expensive than the fluorescent paper. We use metallic label stock for our anniversary seals.