Additionally, from a technical perspective, measuring for a door handle cut-out requires a level of precision which requires knowing how your manufacturer uses the measures provided to fabricate the wood or faux wood blind. This is due to the fact that measures must generally be provided from the bottom of the blind to the bottom and top of the cut-out. Additionally, measures must be provided for how far in the cut-out must notch into the blind. And, there is usually a size restriction on how big the cut-out can be - generally something like 5 1/2". What makes this tricky is that different fabricators may calculate based on window size, outside frame to outside frame, or actual blind height. If you don't know how they do it - and if you guess wrong - then your notch will miss the handle. Oops - that is just annoying.
Of course, there is also a surcharge for this cut - generally around $50 to $100 per blind depending on the fabricator, retailer, and installer. However, with the right advise, knowledge, and application this can be a very convenient custom feature which makes your wood or faux wood project stand out.