N-heptane and Heptane”s”:

Heptanes are a mixture of several isomeric chains, of which, ≥25% is n-heptane.
N-heptane is straight chain isomer of 100% heptane. In layman’s terms, N-heptane is pure Heptane material.

Now, why would one need something so pure as N-heptane? Generally, pure N-heptane is only necessary in pharmaceutical and scientific laboratories. Those industries require precise identification of chemicals and rigid control of all chemical variables.

For artists, architects and home crafters, regular Heptanes are more than adequate for cleaning up inks and rubber cements. You could make an argument N-heptane might be suitable for very expensive or high-tech commercial projects, but one would assume that the budgets for those projects would allow for higher priced materials.

All projects are unique in their own way and each user should always do a thorough job of investigating the best material to use. But if the project does not qualify for one of the higher tier categories described in this article, it would make sense to make the budget conscious choice of choosing the lower cost Heptanes instead of N-heptane.