Jean Blard advertising glass ashtray

This beautiful glass ashtray very transparent with many facets that reflect light beautifully, will keep its secrets! When I examined it in the light, I discovered that it had the inscription "jean blard" engraved (by sandblasting I would say) on the top of the ledge. So it's probably an advertising ashtray, but I haven't found a certain trace of a brand with that name... Unless it is an ashtray that would have been engraved for a person with this name. It probably dates from the 60s or 70s. It has 4 cigarette slots but would also make an original pocket empty. It is in very good condition, neither crack nor shine, barely a few almost invisible scratches in the background. It measures 14 cm side and 4.5 cm high, it weighs 700 g.