Hi Anne, yes, I agree Ikea glass must have been made by glassmakers, does anyone have any idea which? Scandinavian? Any particular style would presumably sell in large quantities, so maybe a lot of unmarked pieces might be from Ikea. (But there don't seem to be many of these two-tone pieces around, and I haven't been able to find an illustration of another exactly like this.) Perhaps I ought to start buying Ikea catalogues now to help in future identifications, although probably you would still regard an Ikea piece as unidentified, i.e. "Made by

, sold by Ikea". Still, it would be a start.
Penelope, thanks for putting me on to another possibility. I've had a quick search for images for Erickson Glass, and managed to find two similar two-tone pieces, although not exactly the same as mine. Did Erickson export to the UK? They seemed to make quite a lot of pieces similar to Whitefriars, lots of controlled-bubble items and also little coloured jugs with clear handles. All this sharing of styles makes life very difficult, although it seems that pieces from some makers were usually signed, so unmarked ones can rule those makers out. Or have I got that wrong?
Thanks again, Valerie