Nowadays, Polypropylene non woven bags are more and more popular as they are getting more attention of consumers. For a company who want to order Customized reusable shopping bags, they need to know what print methods available.

So what print methods available for customized reusable shopping bag?

Customized reusable shopping bag can be worked by below print methods:

1. Silkscreen print

2. Transfer print

3. Offset Gravure print

4. Heat thermal transfer print

Analysis Features Of These Prints:

· Silkscreen print

Silkscreen print one of the most common printing technology, print ink can be water based or oil based or UV. For reusable shopping bag, the most popular ink is water based, which is eco-friendly and cost-effective. Most non woven bags of silkscreen print. If you are going to order shopping bags with a simple logo, like your company name and website address, you can chose silkscreen print. But it can only work pure colour without gradient, like Pantone colour. So when your logo of CMYK colour, like a picture, then we need to turn to other print methods.

Some issues need to be noted when silkscreen print:

1. Since most silkscreen print for reusable shopping bags are water based, so if the print ink come dry, the print plate will be blocked. So have to keep adding moisture during the whole process of printing.
2. When make silkscreen print, the temperature of dryer is very important. Fabric go through driver only in seconds time, and roll up. So print ink would stick to fabric if ink not dried enough.
3. Make sure print position not shift during moving of fabric. Especially when print of two colors, have to make sure each colour positioned exactly as artwork, tolerance normally within 2mm.

· Transfer print

Transfer print widely used for shopping bags, like non woven bag, cotton bag etc, when logo of CMYK colour, with print coverage within 50% of bag size. The advantage is print logo can be CMYK full colour, not like only pure singer colour like silkscreen print, so more vivid. That means any photo or picture can be printed. On the other side, higher cost is the disadvantage, cost is higher than silkscreen print.

The print mainly used on un-laminated fabric bag, like non woven fabric. Cotton fabric.  The process is firstly print logo onto transfer paper, and treat with heat, so the logo move onto bag material from paper.

When you are going to order Customized Bag, with CMYK logo, but small coverage, you can chose this print.

Some issues need to be noted when transfer print:

1. The ink material is depends on fabric material. For example, non woven bag and cotton bag request different ink when work transfer print.
2. Temperature is important during print. If the temperature is not enough, ink would not  move onto fabric, but if too high temperature, ink might damaged, or fabric might be scorched.  
3. Timing control: Only keep seconds of heat treatment during transfer print, and remove the transfer paper.

· Off-set Gravure print

When print logo of CMYK logo, like a photo or picture with 100% coverage of bag. Silkscreen is not suitable, and transfer print is too expensive, then offset gravure print come to the alternative.

This print normally used for paper bag and polypropylene woven and non woevn bag. For paper bag, the print it’s simple, print onto bag. Here we’d like to introduce how the offset gravure print work for PP woven bag and Non woven bag.

For print of PP woven /non woven bag, the 1st step is to make Plate as per artwork, which can be single colour or CMYK. Maximum can be 8 colors, include white background. Go to printing process after plate ready, it’s printed onto plastic film, and then laminated onto fabric like non woven and pp woven material.

You can chose matte or glossy lamination when work laminated PP woven and non woven bag. Different batch of print might of slightly color difference, not serious.

When use such print, fabric most of white colour, because white material as background present best print result.

Some issues need to be noted when offset gravure print:

1. Make sure plate well protected. Since plate is copper plated on surface, which easy to be damaged, it’s better to wrapped by soft fabric and well stocked.
2. Most full colors of CMYK, C = Cyan, M=Magenta, Y=Yellow, K=Black. We can adjust the concentration of any above 4 colors to get the final print effect of logo. For example, we can get dark gray color by adjust concentration of black ink.
3. Make sure fabric is smooth during lamination after printing. Otherwise, fabric would wrinkle.
4. Make sure fabric well cutted after lamination, to cut exactly as it’s position marking, tolerance normally within 0.5mm.

· Heat thermal transfer print

For shopping bag like PP non woven bag and Nylon bag with CMYK print, when you don’t like offset gravure print, heat thermal transfer print comes to an solution.

It works similar like transfer print, but printed by plate, instead small pieces of transfer print paper like transfer print. When use heat thermal transfer print, logo normally of 100% coverage. For PP non woven bag, one layer of transparent lamination need to be put on it’s back, to fill the small holes of non woven pattern, which helps machine catch the fabric and print piece by piece automatically.

When bag made of Polyester fabric, you need to consider the shrink rate before printing, normally, will happen 5% ~ 10% shrink after printing. Or you can enlarge your logo accordingly before printing, to make sure you get the right logo after heat treatment.

Some issues need to be noted when heat thermal transfer print:

1. Make sure surface of fabric is smooth
2. Make sure ink dry enough before moving to next production procedure
3. Sampling before mass production, to finalize shrink rate and adjust your logo size accordingly.

Summary:

For shopping bags, there are print methods include silkscreen, transfer, offset gravure, heat thermal transfer. Different print suitable for different material bag and customized logo.

When you are going to order bag with logo with text or simple logo, like one or two colors, you can chose silkscreen print. When your logo of small size but full colour, like a small picture, you can chose transfer print. When your logo of CMYK color with 100% coverage, you can chose gravure print, which is most popular print for pp non woven and pp woven bag. When you don’t like bag with lamination, heat thermal transfer print might be the option.

For customized reusable shopping bags, different bag material and logo request different print methods. To chose the most suitable and economic print method is important when you are going to customized bag.