Our daughter is newly obsessed with mermaids and wanted to be one for Halloween. My husband and I agreed on these design criteria: it had to be age-appropriate (no shell bikini bras for our 3-year old!), it had to allow for free movement (she’s very active) and there could be no references to Ariel of Little Mermaid fame. I couldn’t find a tutorial online for a mermaid costume that we both liked, so here’s what we came up with by winging it:

Step 1: The Base

The base of the dress was a printed blue cotton fabric with a shirred top. It was a quick shortcut to get the basic shape and structure -- the scales were sewn directly to it. (It happened to be Little Mermaid fabric, so I had actually had to cut Ariel off the print at the bottom...we took some pleasure in this)

Step 2: Making the Scales

The scales were made on a laser cutter in a ‘skip tooth’ pattern that could be assembled in a phased way so that each adjacent scale was different. We cut 3 different fabrics (various shades of blue with different textures) to create 1 strip of multi-colored scales. Tulle was sandwiched between each layer to give the strip some extra dimension; the layers were glued together.

With 1/2 yard of each fabric, we only had enough fabric for creating ~22 complete strips of fish scales; 30 would have been ideal.

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Step 3: Tail and Scale Assembly

The fishtail was cut and sewn, turned right side out, and then sewed to the back dress panel. After attaching the fishtail, I rounded the dress hem so that it followed the curve of the fishtail -- but none of that detail ends up showing, so perhaps this step doesn’t actually matter. Scale strips are layered and sewn one by one, starting from the bottom. I eyeballed the spacing, just trying to make sure there was enough overlap between each strip so that the base dress fabric wasn’t visible. This is how the back looked when done.

Same thing for the front dress panel: scales layered starting from the bottom of the dress, with the first strip hanging slightly below the hem. Then the front and back panels were sewn together, bulky seam allowances trimmed. Finally seashells were attached to the front using a hot glue gun, straps to tie around the neck were added and voila! Mermaid costume complete.