Can you pour wine out of a glass measuring cup on Shabbos, if your purpose was not to measure how much wine there was in the measuring cup. Is a glass measuring cup mukza on Shabbos in all situations?
A glass measuring cup is considered a kli shemilachto l’issur, since it is primarily used for measuring, which is not permitted on shabbos. There are however times that a measuring cup is allowed to be used on shabbos, such as for measuring for a mitzva use (measure a cup of wine for kiddush). Aside from this the cup can be used non measuring purposes. The halacha of a kli shemilachto l’issur us that it may be moved l’tzorech gufo umekomo, for a permitted use of if the place it is occupying is needed. Therefore you may use the measuring cup to pour wine when you are not using it to measure.
Minchas Shabbos 88-25.