The artificial hymen is a plastic bag filled with... yes, fake blood.
And, it is on sale at artificialhymens.com for $27.95:
Known by many names; artificial virginity kit, Chinese hymen, revirginization, revirgination, revirginize, and fake hymen. Artificial hymens are for women who were born without a hymen, broke their hymen during vigorous exercise, engaged in premarital sex and now fears how their future husband will react if he finds out she is not a virgin, and those born with a defective hymen. We provide a cost effective and convenient product for getting your hymen back and you revirginized.