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Facts on Penis Molding (Penis Moulding), and Penis Casting

Casting a dildo directly from one’s own penis is a relatively new phenomenon, but it seems to be catching on as the new standard in custom sex-toys. How to mold a penis? How to cast a penis? Following is some general information on the molding and casting of an actual penis, including which materials to avoid and which to employ in order to yield the best results.

The most important factor to consider when casting a body part is the quality and properties of the molding and casting materials being used. Generally, a sodium alginate* powder is used to form the MOLD (the negative impression), and a type of resin system is used to form the CAST (the positive ‘finished’ dildo). This resin system may be epoxy, polyester, silicone, RTV rubber, or a number of other possibilities.

Can I Use A 3D Printer To Copy A Penis Like Dave Franco's character “Pete” in the Movie Neighbors?
Yes, but you might not want to... YET. Speed and no need for any messy mixing and pouring are the obvious benefits to using a 3D printer over a Penis molding kit. You won't have to mix up a molding powder + water solution and hold an erection for 60-90 seconds to create a mold. All that’s required on the model’s part is to hold his erection long enough for a short video imaging session. Everything else is done on computer. Easy…no fuss, no muss, right? In reality, to pull off the above you’ll need an impressive camera that can scan in three dimensions and create a virtual model of any object, or CAD/CAM software with a compatible camera, the know-how to use it, and a very expensive 3D printer. The $1,000 consumer grade printers simply won’t cut it, as the printable output size is typically too small to print anything other than a micro penis. You can hire a service where all the above is taken care of (see or, but this requires traveling to a location away from home and allowing a technician take images of your erection. If you’re not a porn star or somewhat of an exhibitionist, this could get uncomfortable. The benefit to this method, though, is that these companies will take care of all the rest. The cost is around $250, and it’ll take just a day to see your result. What you’ll get is a plastic copy of your manhood, basically true to size and shape, including some detail but not the tiny veins and ridges and things that make your penis so unique. Constituent plastic filaments are still going to be visible in the final piece, meaning the printed object isn’t totally smooth. Its rough texture would not only be uncomfortable if used internally, but it’ll also have small crevices in it that could support bacterial growth. Additionally, if you're looking for a usable dildo, an object created from a 3D printer isn’t going to be body-safe. For that, they’ll (or you’ll) need to send your copy away to have a mold created from it. That mold is then filled with silicone or some other body-safe material, left to cure, and sent back to you. Voila…your finished, usable copy is then complete. The result is pretty good, but not as intricate as something you’d get from a direct mold and cast process. Using a camera to catch every small detail is just not as precise as forming a mold directly from the actual body part. Our recommendation? Stick with the original Clone-A-Willy kit for now ( They do offer 3D printing as an alternative, but even they still recommend the more accurate mold and cast process.

Use a high-quality, body casting alginate mixed with warm (at least 70 degree F) water. An alginate that has been buffered to set in a specific amount of time will always produce the best mold in terms of detail. Having a definite time-frame that specifies exactly when to insert your penis and when to pull it out is essential to molding an erect penis. A super-fast set alginate is not ideal, as you will lose your erection while mixing and pouring, and a fast-set won’t capture the detail you need to create a life-like replica. Instead, you’ll want enough time to mix your alginate with water, pour it into your molding container, give yourself that last little bit of stimulus to ensure a complete erection, and then insert your penis. Once inserted, you’ll want the mixture to set-up right away (this is referred to as a delayed ‘Snap Set’). Hands-down, this is the absolute best method for molding an erect penis. Empire Labs’ kits (Clone A Willy, Make Your Own Dildo, Clone A Pussy, etc) all utilize a specially-timed ‘Snap Set’ Alginate, allowing the user a specific amount of time to mix, pour, get ready, and once the timer signals, insert themselves for just seconds. Less expensive, Fast-Set Alginates (Dental Alginates) are designed to be mixed in very small amounts, allowing them to be thoroughly mixed with water in just seconds. Molding a penis takes a considerable amount more alginate and water, and thus considerably more mixing time. Ultra Fast-Set Alginates mixed in quantities larger than that for which they’re intended will begin to gel in some areas before you’re even finished mixing it all. You may still get a mold if you’re really quick, but it won’t capture nearly the detail. Without the fine detail, your finished dildo will look like nothing more than a blob. Whether molding your penis alone or with a friend, a buffered, body casting alginate with a workable time-frame is an absolute must.

There are many aspects to consider regarding which casting material to use. First off, you’ll want to use a material that won’t shrink during cure. The uncured rubber material found in any molding/casting kit has what’s known as a linear shrinkage factor. Most Silicone Resin Systems will have a shrinkage factor of .007in/in or greater(1), and compounds that include Latex are far worse. Even this little bit of shrinkage can mean a lot when copying a man’s penis. Look for a casting resin that has a shrinkage factor of .001in/in. or less (as with any kit(2)). No man wants shrinkage when casting his penis! A medically tested, body-safe PLATINUM CURE Silicone is the best casting material available. Even if the company claims Silicone, a TIN CURE silicone is far cheaper and offgasses potentially toxic acids/alcohols. Be sure it’s a platinum cure. The casting material should never give off any odors... this is a good way to tell what you’re using. DO NOT USE a sex toy that offgasses or smells; there are a few ‘dick kits’ on the internet that use questionable materials. You never know what potentially harmful materials could be in your finished piece. Another VERY important consideration when casting is DETAIL. How realistic will your finished dildo be? There are countless factors at play here, and exploring them all would take a great deal of time and space. The simplest, best way to determine how your dildo will turn out is to simply look at the pictures available from the manufacturer. Regardless of whatever claims they make, if the images they have on display don’t look amazing, neither will your finished dildo. Keep in mind that these are the best replicas the manufacturer has been able to produce, and yours most definitely will not look any better.

What To Avoid
Stay away from molding with plaster and plaster products as they are mostly exothermic (they release heat when curing). There is potential for burns to the skin when molding with plaster, and that’s not an area most men would like to scald. Because plaster becomes rigid, it is difficult to handle and remove, especially from body hair. Casting (forming your positive) with plaster is fine, as the plaster won’t come in contact with your skin (this is what Cynthia Plaster Caster did). A plaster cast, however, won’t be as realistic, durable, detailed, or as much fun as a softer, skin-like cast.

Stay away from casting with any chemically harsh materials. Many uncured resins contain TDI’s, or toluene diisocyanates, which have been found to be carcinogenic(3). Empire Labs, Inc. does not use products containing TDI’s. You’ll also want to stay away from Latex. Aside from the fact that latex allergies are quite common, it will noticeably deform during cure, including a great deal of shrinkage.

General Tips
Above all, TRUST the company from which you’re buying. Check the manufacturer – are they reachable? Is there 24 hour live operator assistance? Will the company back-up their product?
Often a good measure of quality / reliability is whether or not you see the product on store shelves. Most shops won’t carry a product that doesn’t perform as it claims or they risk their reputation. Additionally, stores certainly don’t want returns. Also, look for objective reviews on the product. Reviews posted directly on a website may not be valid, so look for articles in magazines and weblogs from names you trust.

A History Of Penis Casting
The Original penis caster appears to be Cynthia Plaster Caster; who developed a name for herself in the 60’s by casting simple plaster copies of musician’s penises. These copies were merely show-pieces and not intended for actual use, but a fun idea. Since then, casting materials and technology have dramatically improved, leading to the finely detailed, flesh-like casting kit one can find today in almost any adult-toy shop. There are currently a few ‘kits’ on the market, many claiming to be the first; a claim nobody seems to be able to substantiate. One such product has changed their date of inception multiple times, perpetually descending their original idea further back into history.

The first ascertainable website to have sold or mentioned an actual ‘Penis Molding Kit’ doesn’t seem to have appeared until 1997(4). The first quantifiable mention of such a kit in the press, as well as the first to publicly go on sale in a store, seems to be in April of 1998, reflected in an issue of the San Francisco Bay Guardian(5), followed by a 1998 article in Playgirl Magazine(6). Finding any verifiable data on the sale of such a kit before this proves unachievable.

Related Terms:
Clone-A-Willy, Make Your Own Dildo, Clone your willy, Dick Kit, Penis Casting Kit, Penis Mold, Penis Replica, Penis cock kit.

*What is alginate? Alginate is a totally safe, rubbery material derived from brown seaweeds. It is commonly used by dentists to form impressions of teeth. Variations are often used as fillers in ice cream, hamburgers, and countless other foods. Top quality alginates contain more alginic acid, which is the most expensive component of the alginate. To capture fine detail such as fingerprints, you’ll need a high quality alginate with a high concentration of alginic acid. Typically dentists don’t use the top quality stuff, so go with varieties designed specifically for body casting rather than cheaper Quick-Set Dental grades.

(1). Science of Silicone Polymers. Centre Européen des Silicones – CES (2005).
(2). Empire Laboratories, Inc. Casting Resin Product Data / MSDS
(3). NIOSH, Current Intelligence Bulletin 53, " Toluene Diisocyanate (TDI) and Toluenediame (TDA) Evidence of Carcinogenicity, December 1989
(4).; (Empire Labs, Inc.). The BODYDOUBLE Kit
,; (C.Y.B.). The Clone Your Bone Kit.
(5). San Francisco Bay Guardian Vol. 32 No. 29 (April 1998). PENIS MOLDING KIT: Abacus Prosthetic (Empire Labs, Inc.)
(6). Playgirl Magazine (Dec 1998).