Some blood blisters can be extremely painful due to bruising where the blister occurred. They are usually packaged in single blister packs or jars. Non-oriented PET sheet can be thermoformed to make packaging trays and blister packs. The rash has sharply defined borders that may blister and ooze. These came in small boxes rather than blister packs. A few days later the skin begins to blister and peel forming painful raw areas. At the blister stage, intense itching is usually present. In rare cases the skin may blister. The fiberglass would blister, causing surface bubbles resembling a bad case of acne. While calcimine was generally stable with oil paint current latex paints blister and peel. In hemorrhagic smallpox the skin did not blister, but remained smooth. Even in the era of blister packs, the role of packaging has not really diminished. Early removal of a blister of crust increases the chances of developing a scar. The majority of figures were packaged individually attached to "cardbacks" in a plastic blister. ProMach acquired Pharmaworks of Odessa, Florida, provider of blister packaging solutions.