16 This category of stamps was applied using a rubber stamp. They appear either on the unglazed surface of ovenwares, over the glaze, or more commonly under a clear glaze. They are usually found alone, but do appear in association with the impressed markings. Individual stamps show variability in the colour of the oxide used, the overall size of the stamp, and the size and arrangement of the stamp's lettering. These variables were recorded and analyzed, but unfortunately there was no significant correlation with the type, size, or colour of the product on which they were found. Some stamps have been seen in only one size and/or colour of oxide, but since these were often the specialized or particular stamps or since the sample size was small, the suggested correlation is not considered significant. For the record, however, these are mentioned. The observed variability in the overall size of the stamps and the size and placement of the lettering is readily accounted for when one realizes that the common stamps were ordered by the dozens. They lasted for only a few months as repeated use caused wear and damage that made the stamps unusable. The colour of the oxides that were used with the stamps included black, white, red, metallic gold and silver, and various shades of blue, green, and brown.

17 The majority of these impressions appear to have been produced by incorporating them directly in the mold; however, a few were obviously produced by impressing a stamp into the wet clay (e.g., M.3.7). As the latter are so few in number, it was decided to include them in this section.

18 This category of markings is all but impossible to date. Their appearance can seldom be used to date the product as the same mold could have been in use from initial production to discontinuation of the product. Furthermore, mold markings are often difficult to read or even to detect. As the mold was repeatedly used, the impression became worn or, if the glaze was heavy, it was often filled in.

19 The evidence suggests that mold markings were not in use prior to the 1920s. Most appear to have been introduced during the 1930s when Medalta started producing its art wares.

20 Because few examples of applied stickers have been seen, the dates during which they were in use are not certain. Probably other varieties existed, but since they were produced using a gummed paper with poor adhesion they were easily lost. Medalta informants suggested that they were used to mark products that had no other clear Medalta identification mark. While this may be true, there are examples where a sticker has been applied next to a clear mold marking. The Medalta staff offered a second explanation: any products made for the export market had to clearly indicate Canadian manufacture and the gummed labels could have filled this requirement.

21 The following chart lists the markings that are combined on a given product together with the dates that have been assigned to them. Eventually such a chart will help to date a specific product more precisely, but that will have to await examination of more products and confirmation of the suggested dates. If the dates are correct, however, then it should be possible to state, for example, that items bearing stamps G.3.8 and M.3.7 (1930-40 and 1931-54) date 1931-40 rather than 1930-54.

23 These markings are usually produced in the mold but occasionally appear in ink and grease pencil and are usually found on a wide variety of products. Crocks, jugs, churns, pickle jars, and ice-water coolers usually bore a prominent indication of the gallons held, made by a stamp under the glaze. Some of these products and others, such as chicken fountains, often had an impressed numeral on the bottom as well. The impressed numerals found on bean pots indicate quarts, pints appear on pitchers, ounces are found on creamers, and one bowl, probably for butter, was impressed "2 LB" [sic]. "Trade sizes" such as 24, 30, 36, 42, and 60 are impressed into the bottom of teapots and at least one type of small bowl, perhaps a sugar or candy bowl. They indicate that the item held 8, 6, 5, 4, and 1 cups respectively. One teapot was impressed "6 CUPS" rather than the trade number. The impression found on vases indicates height, while those on bowls, pie plates, casseroles, and jardinières indicate the effective inside diameter of the product.

24 The most common impression found on the majority of Medalta's art wares was called a "potter's" number by the Symonds. This numerical designation is usually prefaced by an impressed "No.", but sometimes only the numeral is found. These markings were not always permanent. Some were occasionally applied over the finish using ink and, in one instance, grease pencil. This number was believed to designate a specific mold until it was found on products that were different sizes. However, the shapes were the same; only the size differed. It seems likely that this was a style number, used for stock-taking purposes as well as on order forms and catalogues to identify the specific wants of a customer. Unfortunately, as no Medalta art ware catalogues have been seen, it has not been possible to confirm this hypothesis.

25 The first appearance of style numbers in the Medalta stock ledger was in 1931. Prior entries refer to the items by name alone. As it was in 1930 that Medalta started designing and producing its diversified line of art wares, any products bearing a style number probably date from that time. It is unlikely that the few vases and jardinières in production during the 1920s had a style number, but some of the later molds for these products apparently had the style number incorporated.

26 Medalta also assigned names to specific styles. These are usually found in association with the style or shape number, but not always, as in the case of the "Cypress" and "Czma" pitchers. These names have always been in script and the majority have appeared on vases. "Polygon," however, is found on a variety of products, including a teapot, mixing bowl, casserole dish, bulb bowl (style no. 21), and a jardinière (no. 23). The names observed on vases include "Asia" (no. 2), "Edward" (no. 3), "Hexagon" (no. 60), "Amour" (no. 65), "Betty" (no. 70), "Mikado" (no. 90), and "Victory" (no. 131). The Medalta inventory ledger suggests that "Egyptian" may be on vase no. 61, "Rosetta" on vase no. 62, and perhaps "Spills" or "Duco" on some vases no. 104. To date, however, no examples of these pieces have been seen, only pictures of the products or references to them in the inventory ledger.

27 So far only one product bearing the designer's name has been seen - the Winston Churchill jug. It is in script, impressed into the mold, and appears to read "Carter Scott" though the surname is not clear. Presumably other designers' names will be found, but they will probably be few in number. The majority of Medalta's design work was done by Tom Hulme and the only products seen bearing his name are those marked with stamp G.5.9. Apparently Carter Scott did not work for Medalta, and perhaps only those items designed out side the plant had the designer's name impressed into them.

28 Many Medalta products carry numbers which were apparently used to indicate the type of finish applied to the raw product. These numbers refer to the colour of glaze or lacquer, the stencilled or embossed design, or the combination of colour and design. That they were used for this purpose was determined from the inventory ledger which had the number, finish, and product listed together.

29 These numbers are usually penned in oxide as suffixes to the impressed style number, separated by a penned slash. However, some exceptions to this have been observed. One cookie jar carried the penned number "5/49" applied on the lacquer finish; "49" indicated the green tulip pattern, but the meaning of "5" is still unknown. The second exception was a vase, style no. 71, which had "37/36" prominently scratched into the clay prior to glazing. Presumably "37/36" refers to the opaque white glaze on which is found alternating yellow and blue daisies, each with a coloured stem and leaves below; however, these numbers were not listed in the inventory ledger.

30 The following two lists, of "confirmed" and "unconfirmed" markings, contain all relevant information found in the inventory ledger. The first list gives the numerical code and the corresponding colour or motif term, as entered in the ledger, which match the numerals and finishes seen on actual products. In a few cases the ledger recorded only the number and therefore the specific colour or motif term is not presently known.

31 The second list includes numerical designations alone as well as those which had the numeral matched to a specific colour or motif. While none of these numbers has yet been found on products, it is expected that they will be confirmed as more art wares are examined. The list shows several incongruities. Some glazes appearing to be the same have different numbers, while other, obviously different glazes were given the same numbers. Some of these may be transcriptional errors, but as they appeared on listings for different years, they may simply reflect a glaze change from one year to the next. The duplications are presented as recorded.

34 The Ogilvie stamps generally fall into one of two basic formats, round or oval, as illustrated: