Creating an Affordable Prototype If you don't think you need a prototype, think again. Our Product Development Expert shows you how to construct a prototype that won't break the bank.

Q: How important is it to have a prototype of my invention, and where do I find an affordable prototyper?

A: A prototype is essential, especially if you want to license your invention. You can't license or sell your invention from pieces of paper alone (drawings, patents and so on). Most corporations aren't especially receptive to inventions submitted by outsiders to begin with, but without a prototype, you won't get to first base.

There are two main kinds of prototypers: those who do work for corporations and those who are inventor-friendly. Corporation prototypers work from precise specifications and formal drawings known as engineering drawings or mechanical drawings. Inventor-friendly prototypers are used to "napkin" sketches and incomplete specifications. They work patiently with inventors, exchanging information until they have a good idea of what the inventor wants. They're also generally less expensive than corporate prototypers.

The best way to locate inventor-friendly prototypers is through articles and classified ads found in Inventors' Digest magazine. You can subscribe or purchase back issues by calling (800) 838-8808.

An alternative to the Inventors' Digest approach is to search under the heading "Prototypes" in your Yellow Pages. Many directories don't list such a category. If that's the case, try your library's business-to-business Yellow Pages, which covers your whole state.

Other categories to try are "Model Makers" and "Machine Shops." Model makers are often the people who make architectural models and aren't appropriate for your needs so question them closely about what they do. Machine shops are usually too large for your needs because they're often too busy to take on small, one-of-a-kind jobs from inventors, but you might be lucky enough to find one that will work with you.

In the many contacts you'll make (except for prototypers who advertise in Inventors' Digest), always ask if the vendor is interested in small jobs. And try to present professional drawings-the kind that machinists are used to working with. It's advisable to work with a draftsman to create engineering drawings that have dimensions and tolerances.

If you're unsure about how to determine shape, size, tolerance or material, consider buying an hour of an industrial designer's time for advice. This will probably cost you $75 to $100, but the investment will be well worth it in time and mistakes saved in making the prototype. Find these designers under "Designers-Industrial" in your local Yellow Pages or your state's business-to-business Yellow Pages.

Most industrial designers work alone or with one or two others, and are inventor-friendly. But be sure to ask what kinds of products the designer works on, especially if your invention will be manufactured in plastic when in full production.

Jack Lander is a protoyper for inventors. Prior to starting his own business, he worked for several years as a corporate manufacturing engineer and later, as a mechanical design engineer, acquiring 13 product patents. You can contact Jack at (203) 792-1377 or visit his Web site, The Inventor's Bookstore, at www.inventorhelp.com.

The opinions expressed in this column are those of the author, not of Entrepreneur.com. All answers are intended to be general in nature, without regard to specific geographical areas or circumstances, and should only be relied upon after consulting an appropriate expert, such as an attorney or accountant.