Envelope converting can be a confusing and somewhat daunting experience for someone not familiar with all of the requirements. The term simply means taking large, flat sheets of paper either printed or unprinted and die-cutting them and folding and gluing the die-cuts into envelopes. You are "converting" sheets of paper into envelopes; pretty basic stuff. Once you've gone through the process for the first time, it becomes much clearer and easier to understand.
Here are a few things to keep in mind for your first converting job:
Deal directly with an actual converter - Many companies that sell envelopes and have the word "envelope" in their name are NOT converters. It's best to ask first before sending over an order. You'll be better served by those more experienced in the process and doing the job in-house.
Preparation is the key to good results - A good converter should provide you with a specific list of instructions before you begin. Most important is a layout of the printed sheet showing where the envelopes should be placed. This is only necessary if you are printing on the flat sheets before converting.
Not all design ideas are created equal - If the envelope is printed with a solid that bleeds to an edge, the image must wrap-around to the back by at least one-eighth of an inch in order to account for the normal variation inherent in the process.
Understanding what is possible - speaking of variation, this is something that many designers don't take into account when creating their envelope. Cutting paper in large reams and folding and gluing involves some variation - generally one-sixteenth of an inch in either direction. This needs to be understood in order to have a satisfactory result and a realistic idea of what to expect. Something that looks great in a marketer's imagination doesn't always translate to the finished product. An experienced envelope converter can guide you in the right direction for an outstanding result. Why convert? - If you want an envelope that features a large amount of ink coverage, generally with bleeds on most or all sides, the best way to proceed in most cases would be to print on flat sheets and then convert into envelopes. Anything short of that might be able to be printed on a two or four color jet press using pre-made or stock envelopes at a much lower cost. Again, someone experienced in envelope converting and envelope printing can advise you on the best way to go based on a simple inspection of your artwork.
A nicely printed envelope can enhance your image and cause a potential customer to be curious enough to at least open it. Choosing the right envelope company; one which does the envelope converting, printing and manufacturing under the same roof and can make the process easy to understand is a good place to start. Please feel free to contact me for a no-obligation consultation on your envelope questions.