Help With Age On Planter With Underplate

[kardinalisimo]

I got the pot together with the bowl but not sure if it is a matching drip plate or not.
Any help with dating the pieces?
Thanks

[kardinalisimo]

Any suggestions?

[Stan]

I would say mid 20th century, the flower pot is to white to be earlier,

[kardinalisimo]

You could be possibly right but I don't get that with being too white. Does porcelain change color with age? I understand maybe few hundred years would leave some signs but other than that I thought white stays white. Or not?

[Stan]

During the Ming, Qing, and early republic porcelain it was traditional to paint a light blue over glaze on the decorated porcelain, so when I say to white, meaning that it was not over glazed with a bluish over glaze.

[kardinalisimo]

I am sorry if I misunderstand but are you saying that if there is no blue enamel paint used( I guess that what you mean by blue overglaze) then the piece could not have been made during the Early Republic and earlier? 

[peterp]

Pure white glazes were almost unseen before the late 19th century. Therefore, it is safer to assume that most items completely white were made in the late Qing dynasty or later.
The white glaze depends on the whiteness of the clay and glazes. Few clays were very white, and as the glaze is slightly transparent, the darker clay below shows. Apart from this the purity of the glaze also was affecting whiteness. It was just simply not practical at the time to refine these to a degree that they were purely white. Blanc-de-chine uses a clay that is white than the usual porcelain, thus the result overall is very white, but this was also possible only from the 19th century, probably.

I would guess your pot to be sometimes republic period, but it is difficult to assess from when exactly. This is partially due to the colors used. Perhaps second quarter or later?
To me the tray looks as if it does not belong originally to the pot.

[Stan]

Thanks Peter for explaining the white colors in porcelain, could you explain also the the light blue over glaze also, thanks.

[peterp]

Not sure what you mean with "light blue over glaze", Stan. But, if it is the fact that some white glazes have a bluish hue, that is the same reason as with the other colors. Impurities in the clay, the composition of the white glaze, or both.
Commonly white glazes can have a greenish, yellow, pink, gray or bluish hue. I know only that with grayish appearing glazes the content of iron plays a role.