At first he worked as a drawer for the project of constructing the railway connection between Hrpelje and Kozina.
He also wrote the instructions on path-blazing, published in 1922 in the Alpine Gazette (Slovene: Planinski vestnik).
The Knafelc blaze, introduced in 1922, is a white dot inside a red ring.
A variant with a yellow dot in the center is used for the European long-distance paths E6 and E7.
The Knafelc blaze (Knafelčeva markacija) was later used all over Yugoslavia and is prescribed for Slovenia by the 2007 Mountain Paths Act (Zakon o planinskih poteh).