Have a look at: Setting up a Trifold Brochure in Adobe InDesign (CS5) - YouTube
Why do you choose exactly the same size for bleed as for margins? Bleed is if you want to have color up till the limits of the page, to avoid that it is not really filled when printing.
Are you saying you want three 210 x 210 panels per side? In that case you would want to set up the page as 630 wide by 210 high and make your three columns.
Keep in mind that if your prints are mis-cut into the bleed area on one side, the shift will eat into the margin area on the opposite edge, so you might want to use larger margins thn your bleeds, but the bleed allowance you have specified is about twice as much as most would consider normal, so this may not be a problem.
I have now fixed the sizing issue by create a 630 x 210 size document with 3 columns. I will keep in mind your comments on bleeds and margins. What would you consider the normal for a bleed and margin for this type of brochure - full colour to the edge, no border.
Thank you. Jenet
For offset printing, 3mm or .125 inch would be normal for bleed, but if you are printing on a desktop printer or color copier it is not unusual to see as much as 3 mm drift overall in left/right or top/bottom (or both) positioning through a print run due to the way paper is fed in those devices, so your current bleed might be OK, and it won't hurt to be too large.
Margins are just guides, not something absolute. You want to be sure that you allow enough space between the theoretical trim edge and any content that should not be cut off if the trimming is not perfectly aligned with the theoretical page edge you defined. Typically this is at least the same as the bleed allowance, plus whatever minimum space you feel you would want to see. For press I would probably choose a minimum of 6mm, for desktop or copier, 9-12 mm.
Thanks Again Peter,
This is terrific information to know.
All going well with my square trifold brochure now.
Thanks again and good night.
Glad I was able to help.
One further bit, it's not uncommon to trim the inside panel a bit narrower on a trifold (you would not do this if it's accordion fold however). If you are using a commercial printer you should ask them about this and whether you should adjust the layout dimensions or just allow for additional trim.