What's with the gold foam on the banner?

The method of making gold lettering on banners is as follows: 1. First, take a post-it note to carve out the lettering and cut it out.

2. Flatten the banner, and then transfer the adhesive to the banner.

3. Mix styrofoam and gold powder, stir well, and spread it on a banner to dry for one night (about 10 hour).

4. Take down the banner, tear off the redundant part of the post-it note, then smooth it, and iron the words on the banner until golden words are issued.

5. After drying, it becomes a finished product, which can be handed over to customers.