Help to ID Pair of 1930s Drip Glaze Vases

Hello again - here is another of my boot sale finds that I have been unable to identify. Can anyone help?
This unusual pair of vases are made of light orange coloured clay and are covered with a glossy blue, green, brown and white drip glaze, with the red clay showing through in places.
They have some raised decoration round the sides, almost like tube lining but thicker. Round the waists and bottoms of the vases are raised zig-zags, and on the back and front of each is a curious raised geometric design - two overlapping squares with 6 raised dots in one, and one raised dot in the other. They look a bit like the sides of a dice or a square domino. The design has a bit of an Art Deco look, so I'm guessing they date to the 1930s when drip glazes were also quite common.
There is an indistinct impressed mark to the bottom of each. They stand 16.5cm tall.
It would be great if anyone could point me in the right direction with identification.
Thanks, Clare

My first thought was Denbac, but not sure the clay is right.
Got a feeling they may be continental.

Hello - thanks for the suggestion. Denbac is not a pottery I'm familiar with but having looked at examples on the net, the glaze does seem very similar to some pieces. However, as you say, the clay does seem a bit darker, plus I can't find anything with a mark that could resemble this backstamp. I spend a bit more time browsing Denbac and see if I can come up with anything else. Clare