I love my Gift Box Punch Board's extension arm for scoring so I made a ruler extension by attaching a scrap of the SU grid paper to a strip of heavyweight (100 lb) card stock. I scored 3/8" from the end to make a little stand, and trimmed the 0 end so it would not interfere with the punch, then put Dotto on the back.
Works like a charm! Just be sure to use the piece of grid paper with 1/8' inch markings.
And if you want to make other size boxes than the ones listed on the board, you can use these online box calculators along with the ruler: http://www.thecraftyowl.co.uk/boxbuster/
This is online - you enter whole inches and fractional inches separately.
One thing you need to be careful of is whether the box or envelope calculator is for a card size or a given envelope size. I noticed this when I started using craftyowl and the other Excel-based downloadable calculator ( you can request it ScrappedLives » Version 2 Envelope Punchboard Calculator). I would put the same dimensions into each one and get different starting paper sizes and punch measurements.
I think that the crafty owl will give you a envelope to fit the dimensions you enter, so you have to add an 1/8 inch (or more) to width and depth (craftyowl's terminology) if you want a card of that size to fit. The scrapped lives excel formula assumes your measurements are card measurements (like the chart on the punch board), and adds an 1/8 for you. I think it also adds an 1/8 to the box "height" dimension, compared to craftyowl. I remember noticing the scrapped lives boxes and envelopes were roomier so I went and played a bit with the two side by side. I like the interface on Scrapped Lives better - not having to seperate whole inches and fractions - but not everyone has Excel or wants to give their email address to get the file.
Date: Monday, August 4, 2014 GMT Views: 9420