Sleuth, you know I am nothing but honest (blunt perhaps) but definitely honest. So take what you will with a grain of salt, but 99% of these people are saying you are wrong with your idea and you are digging in your heels and sticking out your chin and bellowing "no I am not".
Here's the facts -
1. Your s/o, g/f has asked for a specific gift and even given you details so you know exactly what she wants.
2. After looking at the spice rack, I realize it could be hand made, and possibly even turn out pretty nice. YET, I also know in my heart of hearts that is not a good idea. She has asked for something specific, because she, like most females, has learned that the male creature tends to deviate or become distracted when it comes to the gift giving process. Over time we females have learned we either have to be specific, or we do not get what we want, or we must buy it for ourselves.
3. Fine, you do not want to purchase something with the Martha Stewart stigma, but this is NOT your gift. This is her gift. This is what SHE wants. She has already visualized it complete with the supplied color coordinated filled spice jars hanging in her kitchen. She has wondered if she is possibly getting spices included in her rack that she has never tried before. She is filled with anticipation that she will get EXACTLY what she has asked for from you.
4. Now, agreeing that a spice rack you make might come pretty close to looking like the MS version, but the baby food jars won't work to keep spices fresh. Plus you are gonna be wandering around pulling your hair out trying to fill those jars with spices that are gonna cost a small fortune that won't be fresh inside of a week.
5. So X-Mas day, she opens a gift that is the same size / shape as her envisoned spice rack. It's NOT the same thing. You see the look on her face. It is not joy. You volunteer "baby, I made that for you cause I love ya'. One of two things is gonna happen. She is gonna smile, put on a brave face, pretends she loves it, insist you hang it, and at the very first opportunity things are gonna be broken, missing, a stray skillet is accidently gonna smack it, all the while she will be harboring inner resentment towards you and your gift "I TOLD him EXACTLY what I wanted and he does THIS!!!!" - or - She is gonna to beat the crap out of you then and there with your gift. I would have offered a third, which is what a lot of us do, and that is exchange the gift in a few days when you've forgotten about it, but since you are hand making it, that option is not feasible.
Instead of all this *drama*, why not do one of the following:
1) Suck it up and buy her the darn spice rack she wants. Again, the Martha Stewart thing is NOT for YOU, it is for HER.
2) Forget about the spice rack all together and buy her a pretty piece of jewelry, thereby totally avoiding Martha Stewart products.
3) Buy her a piece of jewelry and then x-mas day, after all the excitement, let her know that you thought about the spice rack and want to make her one with love and joy and yada yada and you should have it ready for her as an after x-mas gift but want her input as to colors, spices, jar shapes, etc. Then the present will be appreciated.
JMO