Hello Kunalc
Measuring window for roman blinds "Outside Mount" is a little different to other blind types.
This is a great question and I will try to explain as best as I can.
When you measure for roman blinds "Outside Mount" Don't forget the stacking height (height of blind when in the raised position) of a Roman Blind is approximately 300mm.
This means you would normally measure above the opening of your window up to 300mm if you do not want the blind to obstruct any of your view.
Most customers measure up to 150mm above the window.
For the sides of the blinds you should measure up to an extra 75mm to 100mm either side of the window opening to give full coverage and also more privacy.
I hope this helps and thank you for giving me the opportunity to clarify this.
Measure Guide Roman BlindsAlso, though it is American imperial not metric, a great resource instructional video can be found here.
Measure Roman Blinds Outside MountRegards
Jeremy
Administrator.
Measuring windows for roman blinds, how to measure roman blinds.
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