The number of parts shipped to you may differ slightly from the quantity ordered, the range being indicated just below the quantity in the Job | Price dialog.
Although 2D parts allow for multiple parts on one screen, when ordering
2D jobs must not have more than 25 parts on the screen and must not take more than 10 minutes of CPU time to price.
It is often useful to have a sample before a full run especially for a new design. In fact, it is common even for experienced engineers to modify a prototype multiple times before getting it right. If you need a sample before a full run, simply begin with a small order. For example, if you plan to run quantity 100 but want to run 2 pieces first to check your design, begin by placing an order for 2 and after you verify your design, place an order for 98. (eMachineShop does not offer to run a few parts for customer approval before continuing with a full run because doing so requires two machine setups which are not included in the computed price.) The best thing to do to minimize the need for samples is to design carefully and have someone else check your design.