Coating Plastic Bags in Latex

Alexander H

I'm currently planning my next project to take to a convention in May. I'm thinking to make some of the details on the body, I'll make an upholstery foam base, cover it in plastic bags and heat shrink them on to create some texture, then apply latex over the top to paint it and to give it a skin like texture. Yesterday I watched the "Make a Monster - Plastic Bag Technology" course where Billy uses some plastic that he's coated in latex. How well does the latex adhere to the plastic bag? And roughly how thick should I make a latex coating to be reasonably durable?

And now that I'm thinking about it... what may be a suitable alternative to latex, in case anyone who wants to interact with the creature has allergies?

This creature puppet will need to compress slightly flying from Australia to Canada in a suitcase, so I need to make sure that the outer layer is durable as I won't be able to do any paint touch ups over there.

Chris Ellerby

Latex should adhere to the plastic bag through its own adhesive properties.  For application, I recommend applying thin layers and slowly building up thickness as each fully dries.  Just keep in mind that as the latex gets thicker it will add weight and it will require more force to stretch.  Latex is fairly durable, even in thin coats, but as it is a natural rubber it will slowly break down over time.  This is accelerated with exposure to UV, oils, or temperature extremes. 

One alternative to latex would be rubber cement.  I would do a small test first to see if this gives you the look you want, and to make sure the solvents do not have an impact on your other materials.   Once the rubber cement has dried you can powder it to remove the tack, and then paint as desired using acrylics. 

To help with the durability you can seal all the paint with a flexible top coat (like a Liquitex varnish in matte or gloss).  Painting it with PAX paint will also help with durability.  You can also tint your latex with acrylic paint, just keep in mind it will dry darker, so as you mix your latex/paint take small samples and dry them with a hair dryer to see how they look as you adjust things.

I would still pack a small repair kit if you plan on shipping it.  Few small brushes and pre-mixed patch colors in PAX paint, a sewing kit, zip ties, duct tape, super glue, hot glue, etc.   Better to be safe, as international travel can have a lot of variables that may cause wear and tear on things. 

If you are using materials like rubber cement and/or latex, and things are not super well sealed, squishing it may cause surfaces to stick together, so powdering it (inside and out) before packing may help.

/Chris

Alexander H

Thanks a heap Chris! I knew rubber cement was used in the latex painting process, didn't know it could be used by itself. Alas it seems that to get enough volume of rubber cement would be quite costly. I'll have to see how I go time wise for this project - it'd be my first time using latex and I don't want to feel too time constrained whilst learning a new material.

Darrell Green

Alexander, sorry to be so late in replying to this but just wanted to offer a different perspective on costs. I saw your Halloween costume entry and then saw this in your historical posts. When doing any one chemical in large quantity, search for it by its chemical name. Most craft supplies, especially adhesives and paints, are industrial supplies that are used for numerous large to massive sized installations. In these much larger quantities, they will sell in gallon jugs on up to barrel sizes and all sizes in between. Buying from an industrial supply house is a real surprise to most people. It will be in a building you have passed a thousand times and didn't know existed. The prices, when compared in ounces, are ludicrously cheaper than the 6oz bottle you priced the first time around. Even if too late for this project, it is a fun exercise to scope out your supply vendors. Often, you will find your adhesive is used in gallon paint cans for ducting sealant and similar, under different names. 

And kudos on your Halloween entry, very cool. I upvoted it already.

Alexander H

Thanks for the advice Darrell! In the end I decided not to use latex for this puppet (would've been too time constrained initially anyway), but I'll get 'round to using it soon enough.

And likewise with your recent Will Turner costume - it's been quite interesting to read the techniques you used to ridiculously accurately make yourself look like other people. Somethin' I don't see often in special effects, so there's a lot to learn there for me.

Darrell Green

That is the joy of Stan Winston School. To have the ability to be anyone or anything through special effects. Just ridiculously cool.