If a shop is retooled with new machinery or if a different manufacturer is chosen to make the plates, different styles of the same license plate may result.  This is particularly common for bases that have been in use for a while.  The most striking example is the Alberta Wild Rose Country plate in use since the early 80s.  Because several manufacturers were used during their lifetime, many different types have evolved.

The most common types include the following variations:

• Dies: The way the serial numbers are shaped is called the die style.  The following illustrates two different die styles on Ontario and Alberta plates:

 

Two die style of the 1938 Ontario.  The latter uses '39 dies.

Two (of many) distinct die styles used on this base.

In earlier days, sometimes the dies were made narrower to fit more numbers on the plate.  A good example is the 1919 Ontario shown below.


Notice the thinner dies used when they made 6-digit plates.

 
• Size:  Since 1957, North American license plates have been standardized to a 6" x 12" size (with the exception of the NWT polar bear plate).  Before that, size would have varied from province to province.  However some provinces adopted the 6 x 12 standard before 1957.  In the earlier years, to save metal, it was common practice to emboss shorter serial numbers on shorter plates.  These are sometimes called "shorties", as the following example illustrates:

The plate on the right is the normal (most common) size.
 
• Color/Tint:  If the paint runs out or is changed mid way through a run, the plates after the changeover may take on a slightly different hue if the match isn't exact.  Notable examples are the '64 NS and '75 Quebec:

 

The latter plate was made near the end of the run (most likely late in '65 as the '64 plate was used for 2 years).  They were probably getting ready to make the '66 plates which used this lighter shade of yellow.

The last of the '75 Quebec plates took on this greenish hue.

• Material:   Two common materials used in making license plates are steel, and more recently, aluminum.  Aluminum has the advantage that it isn't rust-prone but it is more expensive.  Nowadays, most plates are made of aluminum as they are meant to last several years.  Sometimes a switch from one metal to the other will be done mid-way in a run if the supply runs out and needs to be reordered.  Another common switch is to add reflectorization but then the plate design is usually changed as well.

 

The difference in the metal of these two Nfld plates isn't apparent in this picture until you turn them over and observe the corrosion on the steel base.

• Layout: Sometimes the location of the date, slogan or place name may be changed (or eliminated altogether).  Perhaps the most notable example was the elimination of the slogan "The Place to Be In..." on the 1973 Ambulance/Hearse plates in PEI!  A common example is the elimination of the embossed date on a multi-year plate, or the addition of sticker boxes as illustrated below:

 

	In 1978 Ontario eliminated the year from its multi-year plates (which had become redundant by then).  Notice the modification in the sticker box as well.
	Around 1981, sticker boxes were added to the '79 Quebec permanent plate.

• Bolt-hole: A very subtle difference.  The size of the bolt holes may be changed in the stamping equipment resulting in something like this:

 

A few plates in the NB  03/87 base received round bolt-holes.

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