Combining fabrics in garments
It is perfectly fine to combine different fabrics in garments. You must remember when it comes time to clean the garment that the touchiest fabric determines the cleaning method. If all fabrics are washable and were prewashed before use, then you may wash the garment. If any of the fabrics REQUIRE dry-cleaning, then you should definitely have the garment dry-cleaned. Do not be afraid to wash silks if you have tested for color-fastness and prewashed.