Go straight to Glossary of general terms used in packaging

There are many industry specific issue that arise time and time again. I will explain some of the most important ones to help you understand the way this industry operates.

BOX SIZES AND WEIGHT
A box size is always quoted (unless otherwise stated) as the box's internal size. This size should be large than the overall external size of the product going in the box. Generally an allowance of approx 3mm is added to the overall product size to allow for fitting in a box.

When working out sizes of outer cartons to hold a number of inner cartons or units the following points must be remembered.

The overall size of the finished box must be capable of being despatched by normal routes, post, courier etc, all of these companies set specific size limits on package size. Typically 1.5 metre length max and an overall limit of 3 metre length + Girth, check with your carrier to confirm their handling limits.
For your own practical handling sake make sure that the size you arrive at is manageable and practical. Will the carton fit on a shelf, will it go through a doorway etc just basic practical sense will guide you to developing the best size for your products.

There are other size issue relating to the number of box's that can be fitted on a pallet according to the specification. Key issues here are actual pallet size, pallet load formation(actually how they are stacked on a pallet) allowed pallet overhang etc.
Usual pallet sizes are (800x1200) and (1000x1200)

Having arrive at a practical size the total pack weight needs to be considered. Firstly can the pack be lifted, is it a manageable weight, does it exceed the shippers weight limit, is it a safe weight bearing in mind the strict Health and Safety regulations regarding manual handling etc. Also is there a cost premium at the distribution stage for the weight/volume factor. It best for you to check with your shippers on this point for the exact details.

BOX SPECIFICATIONS
When a box specification is set there are normal working tolerances that need to be considered. These relate to actual size and board weight. Manufactured box's can have a variation of + or - 5mm so it is important to judge final size in the light of this. Board grades may vary in paper weight eg 150 GSM Kraft, may actually be 140 GSM again it is important to see how critical these tolerances are in relation to your actual specification. The size tolerance factor can be improved if the box can be Die-Cut.

Quantity
When a quotation is requested it is important to understand that a price for 1000 lots is the price for an order of 1000. If you only require 250 lots the price will almost certainly go up. It is also true that if you ask for 1000 price and you then need to order 2000 lots you could expect to get a lower price.
When an order is placed for specially produced box's there is a risk of 10% variation on the actual quantity ordered.
Another important factor that can impact on volume is the storage space needed to store corrugated, be sure that you are aware of the volume of space needed to store the corrugated box's that you order.

Origination Costs
When a box is Die Cut, A cutting forme is required. This is usually charged as a once only charge. Cost of formes can vary from under £100 up to £1500 depending on the size and complexity of the job.

When a job is printed even 1 colour reference print there is usually a small stereo cost and as the print becomes more complex there would be an artwork and stereo costs. Stereo cost are nearly always quoted subject to sight of customer artwork.