Let me be the first to state my opinion and why I believe its a hoax.
The shroud of Turin became known about A.D. 1357 when it was exhibited in a small wooden church at the French provincial town of Lirey.
When the shroud came into the possession of the House of Savoy it was accepted in some ways as the true shroud of Christ.
Around A.D. 1464 Pope Sixtus IV let it be known that he regarded the garment as an authentic relic.
In A.D. 1578 the shroud was moved to Turin, Italy. It has remained there ever since, except for a six-year period in WW2 where it was removed for safeguard.
The Catholic church is notorious for coming up with all kinds of relics. In their thinking, relics give some kind of authenticity to the church.
Another relic that is given to the people is presented with the suggestion that God gives these kind of things only to the "true" church.
We will all agree that Jesus took a terrible beating. Considering the disfigurement the beating caused, I seriously doubt that any shroud or cloth would have left any kind of identifying mark.
God's word says; "I gave my back to the smiters, and my cheeks to them that plucked off my hair: I hid not my face from shame and spitting (Isa 50:6).
Here it says that His beard was plucked off. This within itself would have caused horrible swelling and disfigurement, as well as the loss of some blood.
"And they clothed Him with purple, and platted a crown of thorns, and put it about His head (Mk 15:17).
We are told that the kind of thorns used in the makeshift crown that went upon Jesus' head were "victors' thorns. They are said to be about six inches long and are strong and sharp.
"...they smote him on the head with a reed" (Mk 15:19).
The Roman soldiers hit Jesus over the head with a reed. You can imagine what this did to Him. They were beating the crown into His scalp as the thorns pressed deeply into His brow. His head must have swelled far beyond its normal size.
"...His visage was so marred more than any man, and His form more than the son's of men" (Isa 52:14).
Jesus endured brutal suffering. He was so bruised, beaten, marred, disfigured, stricken, mutilated, injured, spat upon, and torn that His outward appearance was ghastly to behold.
When a person considers all the things that the Word of God says about the terrible disfigurement of Jesus' countenance ("visage") and the horrible death He died, it seems highly unlikely that any garment placed upon his face would have left any imprint even remotely resembling that of a human. It seems from Scripture that Jesus' countenance was grotesque after the pulling of His beard, the placing of the crown of thorns, and the beating he took upon His head. Considering that the Scripture says His "visage" [face] was so marred more than any man," I think the evidence is fairly conclusive. Any garment placed over Him would have left no recognizable imprint.
Therefore, it is my opinion that the shroud of Turin is not real. It is another relic produced by the Catholic church to deceive a gullible public into believing that the Catholic church is the final authority. The use of relics add to their prestige and authenticity that they are the only true church.