Pre-shaped plastic or aluminum enhancements used as a guide to extend nail enhancements beyond the fingertip for additional length are called:

Multiuse nail forms.

Explanation:

Hello,

Nails extensions have been widely used to provide nails an extra length which is supposed to enhance the nails appearance. In such a way, different types of materials have been enforced in the light of the creation of those extensions which are known as multiuse nail forms which are pre-shaped plastic or aluminum enhancements used as a guide to extend nail enhancements beyond the fingertip for additional length. Materials such as cyanoacrylate (derived from acrylates) and aluminium turn out suitable for the manufacture of those multiuse nail forms as they provide stability during nail enhancement practices.

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