I had to cut my original comment as it was too long. Basically, there is an easier way to make a grid on p/shop. You open a new document the exact size of the squares you wish your grid to have. You then outline this little square document with the stroke function. Then you use that document to "define pattern". Name the new pattern 1" grid or whatever is appropriate (I have several size of grid in my pattern menu now). Open your new 'working' document, add a fill layer with your grid pattern - you now have the correct sized grid grid in it's own separate layer.. Then in another layer on top of the pattern fill layer, you can 'place' your scanned (or otherwise) pattern. In order to have the pattern over the grid, with no white bits apparent, all you do is then 'multiply' the corset pattern layer and this will then sit very nicely with no interference on your grid. You can then start work on scaling as per this tutorial.
juliab: I tried out your gridding method, and it worked great - thanks for sharing it! (One of the great things about Photoshop: there's usually more than one way to do something.) Use Julia's method for an opaque grid. For a lines-only transparent grid, like the one I used in the tutorial, I created a new layer in my 1"x1" file, applied the stroke function to this, then deleted the opaque background layer before defining the file as a pattern.
marianne: Anyone familiar with Adobe Illustrator should definitely give it a go! Most of the methods described for Photoshop scaling will work just as well in Illustrator, and there's the added bonus of being able to manipulate the pattern's lines digitally after the main pattern has been scaled up. (I used the Photoshop-with-pencil-adjustments approach in this article, because that's what I'm most comfortable with, but a short Illustrator test-run proved that my preferred way isn't the only way!)
OK... figured out that it will do... Next question.. What if my proportions are significanty different to those of the original corset (My measures are 34-22-34, Im a B cup, so not all gored corsets will fit my bust if I scale them to my hips, for example) Will I only be able to scale the pattern to one particular measure, such as my high hip measure, and then have to alter the pattern after I've sewn my toile?
galadriel: (As you've discovered, this works great for enlarging the tiny patterns found in books!) Whether historical or contemporary, almost no pattern for a close-fitting garment is going to be an exact match for the eventual wearer's proportions - such is the way of fashion! I do believe that making an initial toile - scaled to fit at least one of your measurements perfectly - will provide the most accurate information about how to alter the other areas of the pattern. Making a first and then a second toile might seem like a lot of extra work, but a good fit is worth the effort. (My previous article showed that the first toile only fit at the high hips and bust, but I had to make vertical and horizontal adjustments elsewhere.)
I am adoring this subject. In spite of using Mac I did not manage to use satisfactorily the Photoshop, used the outdated Corel Draw again. But my doubt is regarding finding the points of the waist, since this pattern has the practically straight modeling., but even so I managed to re-scale the pattern. Tk. for step by step.
Very nice tutorial, especially since you used Photoshop, which is not really designed for this type of work, try using Adobe Illustrator, Inkscape (free) or Corel. These are designed for drawing and you can trace your pattern and modify it on the fly. Also Illustrator tiles nicely into pdf for selling and printing.