There is a great reference book that lists the stamps and marks that Medalta used for their products. It is easy to follow and there are pictures of the stamps with a year range to match the marks. 
It has been interesting to collect different pieces and check the marks to see if we can come up with a date range for when it was produced. 
We have found pieces with imprinted marks, oxide stamps, a white stamp on top of the paint, paper labels and sometimes a couple different marks.
Sometimes you have to look really close or feel the bottom of the piece or even move it to catch a reflection from light to see what is impressed in the bottom of the piece. Someone told us it depended how often they had used the mold and the more it was used the less of an impression was left on the bottom.
There are still lots of pieces that have no mark at all, so it is important tot handle various pieces to feel the weight, color, shape and all the little things that make Medalta unique.
Then of course there are the marks from some of the other companies that produced pottery in south eastern Alberta.
We still don't know all the numbers of vases and the decoration numbers and names but the more we see them and read about them the more we learn and remember. It can be frustrating to look at something and try to remember if we have one in our collection or not, so we have starting carrying an electronic album with us as a reference.
And the search continues..........
