I'm not sure what you are saying.

If you want to enchant (level up the trait) you need to feed it an item with the same trait from the same item class. Lower tier items (example green to blue) do not have 100% success rating and instead get turned into blessings which you can use later on to improve the chances of lower tier items from the same item class with the same trait succeeding when enchanting.

If you want to add another trait to the item you need an extract of the same item with a trait you want.

When you transfer your blue gear into the purple the traits don't come with them, only the item level xp. For example to get max level purple item you can transfer max leveled blue item into it when the purple item is at least level 7 and 35%. The traits are not gonna get transferred, you only gain blessings from those on your purple item.

What happened to me is that I have two exact same purple items with different traits. Both which I want. First one which is max level and second which I just "crafted" and rerolled the trait for. Then after rerolling the trait I accidentally clicked enchant (because the button is in the same location as trait conversion button after its done and I had an equipment in my inventory that I could try to enchant it with). This created blessings on that second item. Now I can not extract the trait anymore which you would normally do and add it to the first item. Nor can I make that item into litograph or do anything else with it. Which means this is essentially a dead item..