Dressing up as inanimate objects can be a fun choice of Halloween or masquerade costume but is also often called for as part of theatrical productions. Luckily, though rocks themselves are quite heavy, creating a hollow object for a costume with realistic rock textures and colors is something you can do with materials that are both lightweight and inexpensive. Make a rock costume of any size and shape in a variety of colors and textures to suit any costume inspiration.
Create a frame for the rock using chicken wire and duct tape. Form a hollow, irregular ball shape using the wire. Make it as large as you like, provided it's big enough for your body to fit in the middle. Leave the bottom of the shape open. Bend and/or tape all loose wire ends flat against the frame to make it as smooth as possible.
Tear the newspaper into strips about 4 inches wide and 6 inches long (or smaller).
Create a wheat paste glue by whisking the flour into the water in the microwaveable bowl. Microwave the mixture for 30 seconds at a time, stirring after cooking, until it becomes gelatinous.
Coat strips of newspaper in wheat paste and wrap them around the wire frame, covering it. Let dry for about four hours (speed this up using area fans, if you like), then apply additional layers, letting every two new layers dry before adding the next. Use at least six layers and up to ten.
Spray paint the rock with a layer of gray spray paint. Let dry.
Cut a hole in the top of the the rock using the cutting wheel on the oscillating power tool. Make this hole large enough for the wearer to pull it over his head or up, around his waiste.
Do “clean up” trimming around the edge of the rock's open bottom, removing rough edges and pokey wire ends.
Apply a layer of granite texture spray over the gray spray paint, coating the rock completely. Do a second coat, if need be, to cover any spots you might miss the first time (though you may like the look of some gray poking out).
Step into the open rock, or pull it over your head. Hold it up, positioning it in place where you'll want it to be (you may need the help of an assistant for this). Stretch pieces of nylon strap over your shoulders and straight down to touch the rock, both front and back, to figure out where they should attach in order to be centered comfortably for your body. Mark these spots in pencil. Remove the rock.
Cut four slots in the rock using the oscillating power tool and a wheel cutting attachment. Make each of the slots about a quarter inch longer than the width of the strips you have and about a quarter-inch wide.
Wear the rock again to fit it with shoulder straps. Weave the straps through the slots you just cut from the inside. Fold them up and around the edge of the costume, pinning the strap to itself up above on all four points.
Remove the rock.
Hand sew the straps at the places where they're pinned. Use a running stitch (over and under, rather than looping around the outside) to cover the inside and outside edges of each of the four folded strap sections.