Flag of Dominica — unofficial construction sheet
Own work.
The government provides some basic information at Protocols for the use of National Symbols

The size of the Flag should be in the proportion 2:1 (width twice the height)
The stripes of the Flag should be of the same size.
The red central emblem of the Flag is a circle.
The breast of the bird is purple.

The Coat of Arms and Flag can be displayed on any background colour, providing that the colours of the Coat of Arms and Flag are maintained.— Extract from Protocols for the use of National Symbols

There is no evidence that the government has ever provided a full geometric specification for the flag. Therefore, this construction sheet is mostly constructed from non-official sources.
For this construction sheet, the dimensions of the six stripes have been matched to the flag drawing shown in  Album_des_pavillons.
The size of the red circle and all the elements inside the red circle are based off of the September 24,2018 version of File:Flag of Dominica.svg, which in turn is a modified version of an Open Clip Art image.  Minor cosmetic changes have been applied to the the parrot, the wooden branch, and the stars.
There is conflicting information as to whether the fimbriation on the stars should be black or yellow; this is documented at Flags of the World (FOTW).

This construction sheet uses a black fimbriation simply because that is what has been used in File:Flag of Dominica.svg since 2006.  The government shows an image with yellow fimbriation at Dominica National Symbols, but the image is of such low quality it is difficult to treat it as on official representation of the flag.
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