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Dimensions for demogorgon flaps:

DemigorgonPattern.PDF

• Sewed to rectangle: 1/2 in tall, 4.172" wide 
• Circumference = 16.6891"
• Diameter = 5.312"
• Flap height = D/2 + .75 (grommet) = 3.406" (can add extra for bulge)
• Flap height + 1.2" sewed part = 3.906"
• Grommet = 1" diameter, flap 1/4" past edge
• Extra fabric for finishing seam = 1/2"
• Width of top of trapezoid = 1.25"

Dimensions for bottom:

Main Bag Circle Pattern.PDF

• Circumference = 16.6891"
• Flaps 1" wide, 1/2" tall

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1. Move the bottom tape towards the mouth to allow for the full seam allowance.
2. Single exterior rectangle.
3. Make wider (and thus shorter)
4. Add loops through closures
5. Remove line holding flap. Replace with rubber bands
6. Add grommet in bottom for bridal to pass through

New Dimensions:

Rectangle:

• Height = 14.875"  Seam allowance = 3/8"

• Width = 17.2" Seam allowance = 1/4" per side
  

Bottom:

Flaps:

• Trapezoidal flaps
• bottom length 4.175"  = circumference / 4

Sources

• Dimensions for main rectangle: