Often times, proper suits and blazers/jackets are made with an interlining material called Hymo, and Hymo is often made with wool. Can this material be sewn into the inside the construction of a linen jacket? Meaning, can a linen fabric and a wool Hymo interlining be layered on top of each other and sewn together, to construct a garment?
Assuming that the Hymo you are asking about is in fact wool then the example you are describing would definitely not be allowed. As this is a classic case of shatnez.
Since hymo is SOMETIMES made of wool and linen (usually canvas and/or animal hair), are we required to check for it?
No need to check if you aren’t sure there’s wool and linen, since it is a sfek sfeka.
To clarify, I am not referring to Hymo fabric that itself is constituted of comingled fibers or threads of wool and linen. I am referring to Hymo that contains wool fiber/thread (no linen). In this case:
Can wool Hymo be sewn/attached to a linen fabric to construct a garment?
In the case where we are unsure if the Hymo contains wool, either because we didnt check beforehand or the supplier doesnt know, do we need to check after the garment has already been made/purchased?
You cannot sew linen with wool. So, I’m not sure what the question is.
In this case it is ok, because of sfek sfeka.