Test strips are unnecessary. You might want to read my article:
And why there in no such thing as a difficult negative to print
It can be found on my web site here:http://www.michaelandpaula.com/mp/onprinting.html
Below is the part about not needing test strips.
Outflanking the print:
I never make a test strip and I strongly advise others never to make one. I think that making test strips is simply a waste of time since they do not provide enough information. If one is making contact prints or enlargements that are of a constant size or a couple of constant sizes, one quickly learns the approximate amount of light needed. If one makes test strips, one learns at best, more or less what the correct exposure is, but one doesn’t learn how much dodging and burning-in might be necessary. Usually, one goes through more paper figuring that out than if one took the approach I call "outflanking."
To use outflanking: Look at a negative, and based on experience take a guess at the proper printing exposure. Try to guess it exactly, but hope you are wrong—at least by a little. I have used far more paper when I have guessed the exposure seemingly correctly than when I was off, whether by a little or by a lot. Why this is so I will get to later. If you are wrong in your guess and the print is either too light or too dark, you are off to a good start. Now make a second print so that you are exactly the same distance on the other side of what you think the correct exposure will be. After this, the correct exposure will usually become immediately evident. Ideally, it will fall somewhere near the middle of the two previous exposures.
Here’s how this works in practice: Let’s say you look at a negative and estimate that it needs a twelve second exposure. You expose it for twelve seconds, but it is too light and you now think the proper exposure should be fifteen seconds. Do not make the next exposure for fifteen seconds; make it for eighteen seconds—outflanking the print. Now you will have one print that is too light and, hopefully, one print that is too dark. Next, step back and evaluate the two prints. Based on your evaluation of the light and dark prints, make what you think is the proper exposure. At this point do not dodge and burn, even if you know you will need to. (The only exception to this is when in the lighter print there are still some areas that are too dark, and in the darker print there are still some areas that are too light.) Let us say you expose this third print for fifteen seconds. Now evaluate this newest print. Because now you also have a lighter and a darker print as well as one that is at least very close to properly exposed, you should be able to easily see if the overall print is a little too light or a little too dark. Perhaps the exposure should have been fifteen and a half, or sixteen seconds, or perhaps it should have been fourteen or fourteen and a half seconds. If the exposure should have been sixteen seconds, make another print for that amount of time, again without dodging or burning-in. By working in this way you can readily come to the exact basic exposure.
It is the lighter and darker prints that give you the understanding of exactly how much dodging and burning-in will probably be needed, and it is with the print following the one that has the correct basic exposure, usually the fourth or fifth print, that you begin to dodge and burn-in. By referring back to the light print and to the dark print you can now see exactly where and how much to dodge and burn-in. Had dodging and burning-in been done sooner, it would have been impossible to tell exactly what results were due to the dodging and burning-in and what results were due to the basic exposure—so make sure not to dodge or burn-in until the correct basic exposure has been determined. Working in this manner, ultimately you will save time and paper. Often you will have a finished print by the fourth or fifth sheet of paper—the first one that was dodged and burned-in.
If on the first print you guessed what appears to be the correct basic exposure, almost invariably you are in for trouble. First of all, you get no information as to exactly how much dodging and burning-in may be necessary, and then, you have what you think is the right exposure, but there is often the nagging suspicion that maybe it needs an additional second or a half second, or on occasion, an additional quarter second (easy to time with a metronome). And so you make another print, let’s say for a second more. And lo, it is better, a bit richer perhaps. Now, what would happen if yet another half second were added? If you try that, you may end up thinking that an additional second is what it really needed, not an additional half second. And conversely, if you add an additional second, sure enough you will think it only needed an additional half second after all. Had you outflanked the print in the first place, usually you will not have to go through all of that, and ultimately you will use less paper rather than more.
Since using a metronome and the outflanking method, I have come to the conclusion that there are no difficult negatives to print. Sure, some prints do need more dodging and burning-in than others, but by timing them with a metronome, that part is always easy. It is rare indeed that I cannot make five prints from a new negative within an hour, and usually it takes less time than that. And it is not because my negatives are always perfectly exposed and developed.
As part of the occasional workshops I teach, I ask the participants to bring their most difficult negatives from which they eventually were able to make a decent print, the ones that took many hours or even days to print. I then print the negative using the methods described above. Even among these negatives from other photographers I have yet to find a truly difficult negative to print—one that has taken longer than an hour to get right.
Michael A. Smith