This costume started as a school project in my technology class, it started as a halloween costume that was supposed to be completely constructed out of cardboard while also being marine themed since our school is by the ocean. It is meant to be simple and able to fit the average middle school child.

I designed and developed a full cardboard shark costume meant for middle school trick or treaters on Halloween. It is fully made of cardboard and slotted construction.

Specifications: ergnonmic for user, able to freely move arms, no or little purchased items and fully assembled using slotted construction.
Limits: Fully made of cardbaord and no restraints/ adhesives.

Step 1: What You'll Need

All the materials and tools needed for this project are listed below, most of which are house hold items.
Tools:
-cutting mat (T1)
-utility knife (T2)
-metal ruler (T3)
-pencil (T4)
-circle template/compass (T5)

Materials:
- 2 pieces of cardboard, each 46 by 47.5 in. (S1)
-cardboard 14.25 by 9.5 in. (S2)
-cardboard 14.25 by 14.25 in. (S3)
-cardbaord 21 by 28.5 in. (S4)

Step 2: Making the Body

1. Place 46 inch side of cardboard (S1) as height, and 47.5 inch side as width
2. Measure 19 inches down side using ruler (T3) and mark using pencil (T4)
3. Measure down another 9 inches using ruler (T3) and mark with pencil (T4)
4. From top point measure 9.5 inches inward using ruler (T3) and mark with pencil (T4); this is the top of the fin for the body
5. From top point, draw a curved concave line to outer bottom point using a pencil (T4)
6. Repeat steps 2-5 on each side
7. Measure 9.5 inches inward using ruler (T3) from the bottom point of fin and mark using a pencil (T4)
8. Measure 9 in inward on both sides of cardboard (S1) using ruler (T3) and mark points using pencil (T4)
9. Draw a curved line down to the bottom points using a pencil (T4)
10. Draw a line on both sides using pencil (T4) up 5 in. from top of fin
11. Draw a curved line using pencil (T4) to each line for the head
12. Measure 5 in. using a ruler (T3), measure a 5 in. radius using a compass/circle template(T5) and draw face hole
13. Draw a line using a pencil (T4) for slits, align to top tips of fins and measure 4.25 in. inward using ruler (T3)
14. Measure to center of body using ruler (T3), measure 2 in. from bottom of body and draw line using pencil (T4) from there up 8 in for slit. (Back only)
15. Measure 2 in. using ruler (T3) down from center of body and center of top slits, from there measure down another 7.5 in. and draw the line using pencil (T4)
16. Place cutting (T1) mat under cardboard (S1) and cut all slits and lines using knife (T2)

Step 3: Making the Support Bars

1. Measure 4.25 inches down 9.5 inch side of cardboard (S2) using ruler (T3)
2. Draw line (T4) down the middle of cardboard (S2)
3. Place cutting mat (T1) under cardboard and cut down the line using knife (T2)

Step 4: Making the Dorsal Fin

1. Measure 11.8 inches along the side of cardboard (S3) using ruler (T3) mark down using pencil (T4) this will be top of Dorsal fin
2. Draw lines to bottom tips of cardboard (S3) using pencil (T4), draw in shape of dorsal fin
3. Place cutting mat (T1) under cardboard, begin cutting cardboard using knife (T2)
4. Cut slit 0.5 inches from bottom of fin using knife (T2)

Step 5: Making the Caudal Fin

1. Place 21 in. side of cardboard (S4) as top
2. Measure 9.5 in. from top using ruler (T3) and mark using pencil (T4)
3. Measure 2 in. left using ruler (T3) and draw a line using pencil (T4)
4. From end of line measure down 1 in. for 0.25 in. slit using ruler (T3) and draw line using pencil (T4)
5. Measure back up 1 in. Using ruler (T3) and continue drawing line using pencil (T4)
6. Measure from that point 4.75 in. left using ruler (T3) and continue line using pencil (T4)
7. Draw a curved line using pencil (T4) to the top left corner of cardboard in shape of a fin
8. Measure from top tip of caudal fin (S4) down 9.5 in. and to the right 5 in. using ruler (T3) and mark point with pencil (T4)
9. Draw a line down to midpoint of caudal fin (S4) using pencil (T4) in shape of a fin
10. From midpoint, draw a curved line in the shape of a fin down to bottom left corner using pencil (T4)
11. Measure 9.5 in. down from point on right side of cardboard using ruler (T3) and mark using pencil (T4)
12. Measure left 2 in. left using ruler (T3) and draw line using pencil (T4)
13. Measure 1 in. up from line using ruler (T3) and draw line using pencil (T4)
14. Measure 4.75 in. left using ruler (T3) and draw line using pencil (T4)
15. Draw curved line in shape of fin from this line to bottom left point of cardboard using pencil (T4)
16. Place cutting mat (T1) under cardboard (S4) and cut down line using knife (T2)

Step 6: Final Parts

Once construction is completed, this is what the parts should look like.

ITEM        QTY        PART NAME
P1              2                BODY
P2              2                SUPPORT BARS
P3            1                DORSAL FIN
P4              1                CAUDAL FIN

Step 7: Assembly

1. Place the back of body (P1) down, insert dorsal fin (P3) into middle slot
2. Insert caudal fin (P4) into bottom slot of body (P1)
3. Place front of body (P1) parallel to back, insert support bars (P2) into slits above dorsal fin (P3)
4. Insert front of support bars (P3) through back of body and front of body (P1)