Don't know if this would work, but this is what I would try:

Draw a line on a piece of paper...imagine that this is the bottom of your place card.

Then draw another line above the first line, where you would want the name written. Be sure that this second line extends longer than the width of the card.

Now lay the place card with the bottom along the first line...the second line should extend to either side of the place card. Then try writing the name just by using the two lines on each side of the card as your guide, by "eyeballing" it (the "two" lines are actually just one, of course).

I don't own a lightbox but there's a way to mimic one:
Like Grace said, take a piece of plain paper and draw a thin line that will be your guide for the bottom of your placecard. Figure out how far above that line your writing line needs to be and draw it in a dark line (I use a Sharpie). Tape that paper to a window or glass door.

Align your cards against the bottom guide line and you should be able to clearly see the writing line through the card. Practice a little, it takes a bit to get used to writing standing up.

Or, buy a light box.

I wonder if just aligning a paper along the line you want to create and writing above it, using the edge of the paper as your guide. When you lift the paper, any wee over-writing will be on it, and you'll have created a straight line; I don't think anyone will notice if a particular letter is nipped at the bottom, they'll just be admiring your straight calligraphy! OR, create a score line and make it look like you intended it to be there! Place 3 little dots on both sides of it, and voila! An EMBOSSED card! ;-D Personally, I'm heading for the computer to create monogram napkin rings using the Edwardian Script font...not as nice as doing it by hand, but this MOB has enough to do! ;-)

Hope something works for you!

I had another thought, too...

When you try drawing a light pencil mark and erasing it, what are you using for your pencil and eraser?

I've had real good luck with this type of thing (drawing guide lines that I later erase) by using a mechanical pencil with 2 or 2B (hardness scale) lead. And more importantly, I think the type of eraser is important. I've found that those white erasers that come in a long tube work the best for not leaving any residue or smudging. You find these erasers with the mechanical pencils in the store.

i was going to suggest a mechanical pencil too, just don't make the line dark and the pencil's eraser should take the line right off. are the cards that slick kind of paper? if they are, that might not work. perhaps you could use the straight edge of a piece of paper as a giude....i think that holding a piece of paper up to a window while writing would get tiresome. do you have a glass table? if you do, you could place a lamp underneath it and you'll have the same effect of the window technique...without a cramped arm by the time you get to your fiftieth card.
hope i could help,
Cassi

Unless the paper is really thick, you may not need a light box to do it dian's way. The last invitations we used came with a card with very dark lines printed on it that we could slip into the envelopes and see when we wrote the addresses, which came out nice and straight. I really appreciated that.

You can also get place card stock that will go into a computer printer. That's what I did last time. I ordered them from a company called Paper Direct. I think they call it "folded business cards," but they work great for place cards. It came with a guide for measurement, but I didn't think it worked well enough; I just chose a pretty font and used trial and error and kept adjusting spacing, etc., until I had it all lined up well (four on a page), and I used plain paper for practicing. Remember to adjust if you have some that need more than two lines. You can print them way ahead, before you get so busy, including cards for people who you still aren't sure are coming (it's much easier to throw away a few extras later than to go back and start it all up again for just a few). All you will need to do at the last minute is to fill in the table numbers, after you have your seating chart, which you really can't do until a couple of days ahead. Have TWO people do this, then double check after you finish -- it's essential to avoid mistakes, because you lose your place when you look from one thing to another. Don't ask me how I know!

Just thought I'd let you know what I found worked well for me: a light pencil line, later erased with a "Magic Rub" eraser (89 cents at the art supply store and the best eraser I've ever used!) I wrote with a silver Uniball Gel Impact pen, and it is superb!

DD and SIL2B decided against place cards, and just went with table cards instead. Thus I had to make 81 cards instead of 231. Count me glad.

Wednesday we drive to the wedding location (9 hours) in our pickup truck, since DH accidentally backed our nice Honda sedan into a sign post this afternoon while fetching it from getting two new tires for the trip. He feels so terrible about it that all I can do is be comforting. I'm sure this is something we will laugh about eventually. Ha ha.

Judy