St. John creates high quality knitwear that should last for years if properly cared for. Per their website the company recommends the following when it comes to caring for your special pieces:
It is recommended to professionally dry clean all St. John garments unless otherwise noted on the individual garment care label, and it is recommended that garments be dry cleaned once or twice each season.
Before storing St. John garments for the season, be sure to have them dry cleaned. Harmful insects are attracted to perfumes and body oils that remain on a garment after use.
Avoid applying perfume after dressing. The chemicals found in fragrances may penetrate the yarn and have an adverse effect on some colors.
If a spill occurs, blot with a white cloth to absorb excess moisture and take the garment to a dry cleaner as soon as possible. Red wine, coffee and other severe stains should be blotted as described above, then flushed with clean, cold water to remove the excess, then blotted again.
St. John recommends dry cleaning whites and light pastel shades as an entire outfit to ensure that their coloring remains consistent.
Graying of whites and light shades can be caused by dirty cleaning solvent. Residue can build up in the cleaning drum and transfer to the knit. Ask your dry cleaner to clean your whites with the day's first load to ensure your garments are laundered in fresh solution.
Severe yellowing can be caused by extended exposure to sunlight, as well as bright or fluorescent lighting.
Removal of buttons is not necessary if covered in foil before dry cleaning.
The application of affixed embellishments on St. John garments is a heat-activated process. Experienced dry cleaners should be able to safely clean and process the garments.
Do not hang your garments on wire hangers. A padded or shaped hanger is best. When hanging, be sure to button and zip up jackets and dresses, making sure that shoulder pads are properly placed on hangers. This will help maintain the original shape of the garment.
Hang flat-front pants and skirts "opened." Pleated pants should be hung "pleat to pleat" or "sideways." Always hang pants and skirts taut on the hangers to avoid sagging at the waistband.
Make sure that your dry cleaner measures your garments, and keeps measurements on file to ensure they are able to block accordingly after dry cleaning.
When packing for travel, fold your garments in half (in thirds for long gowns) and place tissue paper (1–2 sheets) at the folds to prevent creasing. Your suitcase should be full and tightly packed. Tight packing will lessen the chance of shifting and movement in transit that can cause creases and wrinkles in your garments. Upon arrival at your destination, unpack and hang your garments. Any wrinkles or creases should straighten out in a short period of time.
Should stubbord wrinles persist, you can also hang the garment in the bathroom while a hot shower is run and the steam should release any remaining wrinkles and creases.