I have had an Elna for 10 years and before that had a Necchi for 45 years. The Elna is horizontal and the Necchi was vertical. Have never had a problem with thread on either one. Used the thread I still had from the Necchi on the Elna. When I got the Elna from a sewing machine store, they had to show me some pointers about the machine and nothing was told to me about the type of thread to buy. Have been sewing for many years and never heard of this thread theary before.
Rita