by James H. Pence

Arguably, the “reveal” of the invisible black light picture at the end of a chalk drawing is the most important part of the drawing. Often—in my pictures at least—it is the climax, the place where the message of the drawing hits home. Thus, you want to make the most of every black light picture. Here are several tips on how to maximize the invisible picture’s impact.

1. Make sure you buy a black light fluorescent tube rather than an incandescent bulb or the new LED black lights.

I began drawing in the late 1970s and immediately encountered a problem. After the passing of the hippie era of the sixties and early seventies, psychedelic black light posters went out of fashion. It became difficult to even find fluorescent black light tubes. Often they had to be special ordered and you would pay a premium price. On occasion I paid over forty dollars for one 4’ tube—without the fixture. So you can imagine how happy I was to discover black-light incandescent bulbs. They were much cheaper, so as soon as I saw them in a store I snapped them up. I couldn’t wait to get home and try them out in my easel.

I was very disappointed. Even in a pitch black room, the bulbs wouldn’t make the invisible picture appear. I’m not a lighting technician, so I don’t know the technical reasons for this. I just know that if you buy a black light “bulb” rather than a tube, you’ll be seriously disappointed with the results.

This is also true for the new LED black lights. I haven’t personally tried these out, but the reports from other chalk artists have been discouraging.

The good news is that fluorescent black lights have become much less expensive in recent years. So, spend the extra money and get a fluorescent tube black light.

2. Always have a backup black light handy.

There’s nothing more frustrating than getting to the end of a drawing and turning on your black light, only to have nothing happen. Your whole program has been building up to the big “reveal” and then it all fizzles. This has happened to me a couple of times, and it’s especially disappointing if your audience has seen you (or another chalk artist) before. They’re anticipating the black light picture, too. What a letdown when it doesn’t appear.

A simple solution to this problem is to ALWAYS have a hand-held black light plugged in and ready. That way, if your main light fails, you can quickly pick up the hand-held and put it up to the drawing. You can buy 18-24” black lights in “under cabinet” fixtures at most home supply stores (e.g. Home Depot, Lowes), and even at WalMart. You can also buy them online. (Just Google black light for online sources).

3. Darken the room as much as possible.

I went. I wanted the auditorium where I drew to be as close to pitch black as possible. Ever since I started drawing in prisons (where I’m not allowed to darken the room), I haven’t been quite so picky about it. Nevertheless, it almost goes without saying, but the darker you can get the auditorium or room where you are drawing, the more dramatic your black light will appear. I used to carry a roll of heavy black plastic and masking tape wherever I went. Nowadays, I kick that responsibility back to my hosts. I tell them that if they want to get the maximum effect from the black light, they’ll need to darken the room.

However, it’s not a bad idea to bring a roll of black plastic, masking tape, and a Stanley knife.

Just in case they forget.

4. Add reflective material around your black light.

There are going to be times when you can’t get a room as dark as you’d like. You can compensate by getting rid of black light “leaks” by positioning reflective material behind the light.

If you focus and direct your black light down toward your paper by putting reflective material behind it, you can increase the brightness of your invisible picture. This doesn’t need to be expensive. Aluminum foil works well. I’ve also used a reflective “sun shield” (the kind you put inside your car windshield during the hot summer months). Both of these help minimize black light “leaks” and direct that UV energy down toward your paper. If you want to spend a bit more money, you can buy Coilzak from Eternity Arts (eternityarts.com). It’s a high quality reflective material that can significantly increase the output of your black light.

5. Draw a large black light picture.

Always take into account the size of your venue and audience and adjust the size of your black light effect accordingly. If you’re drawing in a large auditorium but the figures, faces, objects in your picture are too small, your black light effect will look like a very colorful blob to the people sitting in back. I always try to draw my invisible picture large enough so that someone in the very back row will have no difficulty figuring out what the picture is.

Hope these tips help.

Remember to keep drawing. And have fun.