dumb newbie questions

[Chunk]

hi folks --

i'm a newbie here (very first post), and am thinking about getting into screen printing a bit to produce some reproduction bmx bicycle stickers & softgear accessories. i've been researching screen printing info for a few years, but still don't know much about it. i'd appreciate any info any of you could offer on the following questions:

1. one of the items i'm hoping to produce are what's known as bmx frame pads -- cloth-and-foam pads to protect the rider from banging their body on certain parts of the bike. these pads have a covering of nylon fabric that is pretty much like the stuff that kids' school backpacks are made of -- fairly coarse material & available in many colors.

what type of ink and screen mesh count would be best for printing on this type of fabric? my local supplier carries this line of inks called "inktech", and of that brand, i'm guessing that either their "am" (acrylic modified) or "gp" (general purpose) may be suitable, but am not sure.

regarding the mesh count, i've been told that 110 is pretty standard for t shirt printing, and 230 is typical for vinyl stickers, so i'm guessing somewhere in between might be right for this (160 maybe?).

any tips on this would be appreciated.

2. what off-contact distance would be suitable for printing on this material?

3. i've got a few different pieces of mesh fabric that i picked up a while back, but forgot what count they are. is there a standard method for determining the count of a piece of mystery fabric? like maybe counting the threads in 1/10" under a loupe & multiplying by 10? if that's the way to go, does the fabric need to be stretched to get an accurate count?

4. for exposing screens, i've putzed around with a photoflood bulb, which has worked pretty well. i made up some small screens for testing exposure times, with el cheapo fabric-store organdy fabric that i'd stretched in small frames. would this method, even though using different
fabric for the test screen than would be in the real screens, be reasonably accurate?

5. i've been scrounging whatever scraps of mesh fabric i can get on ebay, without much regard to whether it's white or yellow. is there some
approximate figure or percentage that you have to increase the exposure time when going from white to yellow fabric of the same mesh count?

6. i've got some autotype emulsion that i mixed up in (don't laugh) early 2003. it's been in a tightly closed opaque container, in a dark cool place since then. is there any remote possibility it may still be good?

7. assuming it's not, what would you recommend for a decent, reasonably-priced emulsion?

8. any tips on cheap film positives in around 11" x 17" size? i've putzed around with photocopies on transparency film and vellum, but they never seem opaque enough. and i tried that spray that's supposed to darken photocopy toner, and it did nothing. i once got a few positives from westar, that seemed really good, but kinda costly. and advice on workable alternatives? (my stuff is mainly solid lineart areas -- no halftones or linescreens yet). i also tried rubylith on clear film, but it was pretty laborious for the art i was working with.

and, if it matters, i don't have an inkjet printer big enough for 11 x 17, so i can't use that special inkjet film.

thank you very much! screen printing is really intriguing, but also kinda scary.

[Roger Jennings]

There are 8 video subjects on www.youtube.com that would give you a better idea of what is involved. They are all listed at the top of www.rjennings.com. All are free. Beyond that, you will have to ask your favorite supplier. The challenge will be finding someone qualified to give you the right answers. Roger Jennings, R Jennings Mfg. Co.

[krosbones]

These of course are just my suggestions....

1. OneStroke Inks is a quality ink that is pre-mixed with additives for printing on nylon and like substrates. There is also Nylo-Bond, made by Union Ink which is an additive you add yourself to any plastisol ink to make it "bond" to nylon.
Mesh count I would say stay in the 190s and above to get a nice crisp print. When using Nylo-bond, the ink gets thin and runny....a low mesh count will end in a big mess.

2. You will probably hear 20-30 different amounts for off contact...I use the old "Nickle" distance...and works great for almost everything I print.

3. Unless this is all just for fun....don't even waste time with guessing old mesh counts....buy new screens and keep them marked for accurate screen choice. The prices of aluminum framed screens has really came down in the last few years, and they are stretched nice and tight...very little chance of Moray from improper stretching....Try suppliers like Reece, or Graphic Solutions.

4. Thats a hard one to answer...too many varibles....If you stretch your own screens...and they are "looser" than the bought screens...you could end up with a heavier deposit of emulsion due to lack of tension...this would require a longer "burn" time in most cases...I have learned the hard way..that if I am going to test something....the test objects have to match the final objects...(dont test a race track in a VW bug, then race that track in a Viper)
Another suggestion would be...use capilary films instead of liquid emulsion...that way you know that each screen has an accurate "coat of emulsion"

5. This again depends on you exposure unit or method...I use Beamed Black Light so there is no difference in time for my exposures between white or yellow mesh...Do not know what to tell you for this one...

6. Old emulsion is a hit or miss...I would not use any emulsion older than 1 year....It might coat and burn just fine...but when you go to reclaim your screens, there is a chance it will never come out of the mesh...gets locked up....

7. Most screen printing suppliers have their own brand name of emulsion...these are good emulsions and very reasonably priced...for example...I can get a gallon of PS1 from Reece for about $50...but look around...I use Ulano QX1, great emulsion, dries fast and I only pay $55/gal.

8. Sorry no help either....I refuse to use laser printers or any type of vellum....I use an Epson 3000 inkjet and accumark films...11x17 films are $72 for 100 sheets....

Good luck and hope I could be of some help

Kros

[ROADSIDE]

I really hate long posts like this.... Takes me 10 minutes to read them only to say ...... OUT SOURCE!
Find someone to print what you want and the quiz them on what equipment to use.
Printing on Nylon is not the funnest thing to do.